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Some variables affecting belief in a pro-food additive message Campbell, Shelagh Ann 1983

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SOME VARIABLES AFFECTING BELIEF IN A PRO-FOOD ADDITIVE MESSAGE by SHELAGH ANN CAMPBELL B . S c , The U n i v e r s i t y Of Guelph, 1977 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES (Department Of Food S c i e n c e ) We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA A p r i l 1983 © She l a g h Ann C a m p b e l l , 1983 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree that p ermission f o r e x t e n s i v e copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s or her r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . Department of Food Science The U n i v e r s i t y of B r i t i s h Columbia 2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5 Date: 22 A p r i l 1983 A b s t r a c t S e v e r a l surveys document the m i s i n f o r m a t i o n that e x i s t s among consumers about the use and s a f e t y of food a d d i t i v e s . I t i s i n the i n t e r e s t s of a we l l - i n f o r m e d consumer that food s c i e n t i s t s attempt t o e x p l a i n c o n t r o v e r s i a l food i s s u e s i n an understandable manner. The o b j e c t i v e i s f o r consumers to have the i n f o r m a t i o n a v a i l a b l e i n order to make informed c h o i c e s i n the marketplace. Questions have been r a i s e d as to the acceptance of in f o r m a t i o n designed to c o u n t e r a c t the m i s i n f o r m a t i o n . The problem i s that much of t h i s c o u n t e r - m i s i n f o r m a t i o n i s d i r e c t l y o p p o s i t e to the c u r r e n t negative s o c i e t a l s t e r o t y p e about food a d d i t i v e s . T h i s r e s e a r c h examined the r o l e of the t r a d i t i o n a l a t t i t u d e change v a r i a b l e source c r e d i b l i t y , as w e l l as r e c e i v e r a t t i t u d e towards food a d d i t i v e s , as f a c t o r s i n f l u e n c i n g b e l i e f i n a pro-food a d d i t i v e message. An a t t r i b u t e - treatment - i n t e r a c t i o n (ATI) model was used f o r the design of the study and r e s u l t s e v a l u a t e d by l i n e a r m u l t i p l e r e g r e s s i o n a n a l y s i s . A q u e s t i o n n a i r e c o n s i s t i n g of a measure of a t t i t u d e ; a measure of b e l i e f i n food a d d i t i v e statements; a pro-food a d d i t i v e message and a measure of b e l i e f i n the message was developed. The message was a t t r i b u t e d to one of three sources that had been p r e v i o u s l y r a t e d as c r e d i b l e r e g a r d i n g i n f o r m a t i o n about food a d d i t i v e s . For the c o n t r o l , the message was a t t r i b u t e d to no p a r t i c u l a r source. R e s u l t s i n d i c a t e d t h a t none of the sources were able to produce st r o n g b e l i e f i n the pro - f o o d a d d i t i v e message. The a t t i t u d e ; the b e l i e f i n statements and the sources accounted f o r 49.23 % of the v a r i a n c e i n b e l i e f i n the message. An i n t e r a c t i o n e f f e c t between source and a t t i t u d e was found to be s t a t i s t i c a l l y s i g i n i f i c a n t . Based on t h i s l i m i t e d study, i t appeared t h a t , f o r the p o p u l a t i o n t e s t e d , the n u t r i t i o n i s t had the same e f f e c t on b e l i e f i n the message, r e g a r d l e s s of the a t t i t u d e of the r e c e i v e r of the message. For r e c e i v e r s who h e l d a n t i - f o o d a d d i t i v e a t t i t u d e s , the n u t r i t i o n i s t was most e f f e c t i v e at i n f l u e n c i n g b e l i e f i n the message. i v Table of Contents A b s t r a c t i i L i s t of Tables v i L i s t of F i g u r e s v i i Acknowledgements v i i i I. INTRODUCTION 1 I. THE GENERAL PROBLEM 4 I I . SPECIFIC PROBLEMS 4 I I I . DEFINTIONS 6 I. SOURCE CREDIBILTY 6 I I . ATTITUDE 6 I I I . BELIEF 7 IV. DIMENSION 7 V. CONSTRUCT 7 VI. CONNOTATIVE/DENOTATIVE 7 IV. RESEARCH HYPOTHESES 8 V. METHOD OF STUDY 9 I. POPULATION 9 11 . THE SAMPLE 9 I I I . INSTRUMENTS USED 9 i . Presurvey 1 9 i i . Presurvey 2 10 i i i . Main Survey 10 VI. ANALYSIS OF RESULTS 11 V I I . LIMITATIONS 11 VI11 . SAFEGUARDS 12 I I . LITERATURE REVIEW 14 I . BACKGROUND TO THE PROBLEM 14 I. SOCIOLOGICAL 15 I I . EMOTIONAL 16 I I I . PSYCHOLOGICAL 17 IV. MISINFORMATION 19 V. LACK OF RELIABLE INFORMATION 21 VI. EDUCATIONAL 22 V I I . POLITICAL/GOVERNMENTAL 23 I I . SOURCE CREDIBILITY 24 I . MAIN EFFECTS 29 I I . INTERACTION EFFECTS 31 a. AUDIENCE VARIABLES 32 i . P s y c h o l o g i c a l C h a r a c t e r i s t i c s 32 i i . Other Audience C h a r a c t e r i s t i c s 34 b. MESSAGE VARIABLES 37 i i i . Arguments i n the message 37 i v . Message S t y l e 39 v. Use of Evidence i n the Message 40 v i . Discrepancy 42 v i i . Threat 44 v i i i . I n c o n g r u i t y of Message 44 I I I . THEORIES TO EXPLAIN THE SOURCE EFFECT 47 I. COGNITIVE RESPONSE THEORY 48 I I . CONGRUITY THEORY 56 I I I . SELF PERCEPTION THEORY 60 V IV. ATTRIBUTION THEORY 62 V. COGNITIVE DISSONANCE THEORY 65 VI. LEAST EFFORT HYPOTHESIS 66 IV. RELATED STUDIES 67 I I I . METHODOLOGY 71 I. POPULATION 71 11 . THE SAMPLE 71 I I I . THE INSTRUMENTS 72 I. PRE-SURVEY ONE, CHOICE OF SOURCES 72 I I . PRE-SURVEY 2, SELECTION OF STATEMENTS 77 I I I . THE MAIN SURVEY ...85 a. General D i r e c t i o n s 85 b. Part 1 - Your Opinion 86 i . D i r e c t i o n s and Example 86 i i . The Measure 86 i i i . S c o r i n g the Measure 86 i v . R e l i a b l i t y T e s t i n g of the Instrument 89 c. Part 2 The Message 92 d. Part 3 - Your Reaction to the Message 93 v. D i r e c t i o n s and Example 93 v i . The Measure 93 IV. ANALYSIS OF THE RESULTS 94 I. DESIGN 94 II . THE MODEL 95 i . E f f e c t Coding of Treatment V a r i a b l e s 96 V. STATISTICAL HYPOTHESES 96 IV. RESULTS 99 I. MULTIPLE REGRESSION ANALYSIS 99 I I . THE SIX STEPS IN THE ANALYSIS 103 I. STATISTICAL HYPOTHESIS #1 104 I I . STATISTICAL HYPOTHESIS #2 104 I I I . RESEARCH HYPOTHESIS*3 109 IV. RESEARCH HYPOTHESIS #4 110 V. PROPORTION OF VARIANCE INCREMENT 111 I I I . ANCILLARY RESULTS 112 I. FREQUENCY DISTRIBUTION OF SCORES 112 I I . MESSAGE BELIEF SCORES COMPARED BY SOURCE 119 V. SUMMARY AND CONCLUSION 123 APPENDIX A - PRE-SURVEY ONE 126 APPENDIX B - PRE-SURVEY TWO 133 APPENDIX C - THE MAIN SURVEY 136 APPENDIX D - DEVELOPMENT OF THE SURVEY INSTRUMENTS 148 I. PRESURVEY 1 - RATING OF SOURCES 148 I I . SCORING THE ATTITUDE MEASURE 149 APPENDIX E - THE INSTRUMENT - ANALYSIS OF RELIABILITY ...155 I I I . STEPS IN INSTRUMENT DEVELOPMENT 155 IV. MULTIPLE REGRESSION ANALYSIS 177 V. MEAN SCORES OF RESPONSES 179 BIBLIOGRAPHY 183 v i L i s t of Tables I. Source C r e d i b i l i t y Measurement S c a l e s 73 I I . Scores and R e l i a b i l i t y of Source C r e d i b i l i t y Measure 74 I I I . Food A d d i t i v e Statements Used i n Pre-survey #2 80 IV. Corresponding P o s i t i v e Statements 82 V. Coresponding Negative Statements 83 VI. Ranking of Statements as P o s i t i v e or Negative 84 V I I . Summary of Analyses of Instrument R e l i a b i l i t y 91 V I I I . C o r r e l a t i o n M atrix of V a r i a b l e s i n the Regression Equation 100 IX. Test For M u l t i c o l l i n e a r i t y 101 X. ANOVA For the F u l l Model 102 XI. M u l t i p l e Regression A n a l y s i s - F u l l Model 103 X I I . Mean Scores and Frequency of Response f o r the BELIEF MEASUR 113 X I I I . Response Frequency of Mean ATTITUDE Scores 115 XIV. Response Frequency of Mean MESSAGE BELIEF Scores .117 XV. Mean B e l i e f i n Message Scores Grouped By Source ...119 XVI. B e l i e f i n Message Over Three A t t i t u d e L e v e l s 120 XVII. RATING OF SOURCES - ITEM STATISTICS 148 XVIII. Subtest - S t a t i s t i c s - Source of V a r i a n c e 149 XIX. R e l i a b i l i t y of ATTITUDE MEASURE T o t a l Test 160 XX. T o t a l T e s t S t a t i s t i c s - ATTITUDE Measure ..161 XXI. R e l i a b i l i t y of BELIEF Measure T o t a l Test 162 XXII. T o t a l Test S t a t i s t i c s BELIEF i n Statements Measure 163 XXIII. R e l i a b i l i t y of T o t a l T e s t , ATTITUDE Minus Iteml on A n t i 164 XXIV. Test S t a t i s t i c s - ATTITUDE - Minus Iteml on A n t i ..165 XXV. R e l i a b i l i t y of T o t a l T e s t , Minus Item 4 Pro BELIEF 166 XXVI. Test S t a t i s t i c s (Minus Item 4 Pro) BELIEF Measure .167 XXVII. R e l i a b i l i t y of Pro Statements Only ATTITUDE 168 XXVIII. Test S t a t i s t i c s Pro Statements Only - ATTITUDE ....168 XXIX. R e l i a b i l i t y of Pro Statements Only Test - BELIEF ..169 XXX. Test S t a t i s t i c s Pro Statements Only - BELIEF 169 XXXI. R e l i a b i l i t y of A n t i Statements Only Test - ATTITUDE 170 XXXII. Test S t a t i s t i c s ( A n t i statements only) ATTITUDE ...170 XXXIII. R e l i a b i l i t y of A n t i Statements Only Test - BELIEF .171 XXXIV. Test S t a t i s t i c s ( A n t i Statements only) BELIEF 171 XXXV. R e l i a b i l i t y of Pro Statements Only Test -BELIEF (Minus v i i Item4) 172 XXXVI. Test S t a t i s t i c s (Pro Statements Only) BELIEF 172 XXXVII. R e l i a b i l i t y of A n t i Statements Only Test ATTITUDE .173 XXXVIII. Test S t a t i s t i c s ( A n t i Statements Only) Minus Item 1 173 XXXIX. R e l i a b i l i t y of A n t i Statements Only Test BELIEF ...174 XL. Test S t a t i s t i c s ( A n t i Statements Only) -BELIEF ....174 XLI. R e l i a b i l i t y of A n t i Statements Only Test - ATTITUDE 175 XLI I. Test S t a t i s t i c s - ATTITUDE 175 X L I I I . R e l i a b i l i t y of A n t i Statements Only Test - ATTITUDE 176 XLIV. Test S t a t i s t i c s ( A n t i Statements Only) - ATTITUDE .176 XLV. R e l i a b l i t y of Measure For BELIEF IN MESSAGE 177 XLVI. T o t a l Test S t a t i s t i c s 177 XLVII. C r i t e r i a f o r S e l e c t i n g Data 178 XLVIII. Summary of M u l t i p l e Regression Analyses on V a r i o u s Data 179 XLIX. Response Frequency of Mean BELIEF Scores -A n t i Statements 180 L. Response Frequency of Mean ATTITUDE scores -A n t i Statements 182 v i i i L i s t of F i g u r e s 1. C r e d i b i l i t y Ratings of Sources of Food A d d i t i v e Information 76 2. Graph of Treatment Regression Planes 108 3. Histogram of Mean Response Scores f o r BELIEF i n Pro-Statements 114 4. Histogram of Mean ATTITUDE Scores 116 5. Histogram of Mean BELIEF i n MESSAGE Scores 118 6. Graph of Message B e l i e f v s . A t t i t u d e L e v e l 122 7. Histogram of Mean BELIEF scores - A n t i Statements ...181 8. Histogram of Mean ATTITUDE Scores - A n t i Statements .182 ix Acknowledgement There are many people who have a s s i s t e d i n the pr o d u c t i o n of t h i s t h e s i s . I warmly thank them f o r t h e i r input and encouragement. In p a r t i c u l a r , Dr. Walter Boldt p r o v i d e d much t e c h n i c a l guidance as w e l l as kind encouragement an ongoing suppport. I would a l s o l i k e to thank my Committee a d v i s o r , Dr. John Vanderstoep f o r h i s i n t e r e s t s i n a somewhat unique res e a r c h p r o j e c t ; and Dr. Jim Richards and Dr. W i l l i a m Powrie f o r t h e i r v a lued comments and a d v i c e . Thank you to the UBC psychology of education students who p a r t i c i p a t e d i n the survey. The Education Research S e r v i c e Centre was most h e l p f u l with the computer a n a l y s i s . And,the l a t e n i g h t s e s s i o n s were made bearable by my c o l l e a g u e s Anne-Maire Pham, Kent Kwan, S y l v i a Yada, C h e r y l C r a i g and Tom Tautorus. I thank them very much f o r a l l the r i d e s home. F i n a l l y , I would l i k e to thank my parents, Walter and June Campbell f o r t h e i r long d i s t a n c e m o t i v a t i o n when the going got rough. 1 I. INTRODUCTION I t i s w e l l documented that c o n f u s i o n and m i s i n f o r m a t i o n e x i s t about the use and s a f e t y of food a d d i t i v e s . Surveys show that some members of the p u b l i c h o l d b e l i e f s about food a d d i t i v e s that are unsupported by s c i e n t i f i c evidence (Anderson and Standal,1975; Boocock,1978; Duffek,l978; Knox and S c h r e i b e r , 1980; Martinsen and McCullough,1977; Z i b r i k et a l , 1980). Some of these b e l i e f s a r e : 1) Commonly used food a d d i t i v e s present a h e a l t h hazard (Knox and S c h r e i b e r , 1980). 2) Food a d d i t i v e s are u b i q u i t o u s to a l l foods (Knox and S c h r e i b e r , 1980). 3) A d d i t i v e s are used f o r company p r o f i t at consumer expense (Knox and Schreiber,1980). 4) C o n t r o l s on food a d d i t i v e s are inadequate ( Z i b r i k et a l . ,1980). 5) Processed foods ( i e . food a d d i t i v e s ) are r e s p o n s i b l e f o r degenerative d i s e a s e s (Broad,1979). 6) Food a d d i t i v e s are unnecessary (Knox and S c h r e i b e r , 1980). 7) Food a d d i t i v e s make food l e s s s a f e . ( Z i b r i k et a l . , 1980) S e v e r a l t h e o r i e s have been proposed to e x l a i n why these misconceptions e x i s t . They may be p a r t of a food fad, where 2 c e r t a i n foods are e l i m i n a t e d from the d i e t due to b e l i e f that harmful c o n s t i t u e n t s are present (Bruch, 1973). Other reasons i n c l u d e s o c i o l o g i c a l 'back-to -nature' trends (Clydesdale,1980; Saegert and Saegert,1976); the emotional a s p e c t s of food consumption (Clydesdale,1980); i n d i v i d u a l p s y c h o l o g i c a l background equating s e c u r i t y with p u r i t y (Bruch, 1973); a perponderance of m i s i n f o r m a t i o n due to s e n s a t i o n a l i s m i n the press (Harper,1979; Sloan,1981; Young and S t i t t , 1981);a lack of r e l i a b l e i n f o r m a t i o n due to the experts not communicating (Harper,1979; S t i l l i n g s , I980);as w e l l as p o l i t i c a l and e d u c a t i o n a l problems ( C l y d e s d a l e , 1980, F r a n c i s , 1979). Some i n f o r m a t i o n on f o o d - r e l a t e d i s s u e s c o u l d be detriment-a l to h e a l t h , such as the promotion of l i q u i d p r o t e i n d i e t s that caused deaths due to l a c k of n u t r i e n t s (Van I t a l l i e , 1978). However, most of the unfounded food b e l i e f s mentioned above do not a f f e c t the consumer t h i s way. Instead, the problem manifests i t s e l f as a l a c k of sound i n f o r m a t i o n on which to make ch o i c e s i n the marketplace (Duffek,1978). Advertisements t h a t promote " n a t u r a l " or " a d d i t i v e - f r e e " foods take advantage of consumer concerns and ignorance. " U n f o r t u n a t e l y , consumer p e r c e p t i o n i s not always c o n s i s t e n t with r e a l i t y and f a c t . For example, consumers p e r c e i v e ' n a t u r a l ' i n g r e d i e n t s to be more h e a l t h f u l and f r e e from hazards than ' a r t i f i c i a l ' i n g r e d i e n t s . S c i e n t i f i c a l l y , we know that t h i s i s not the case. Rather than standing f i r m on the f a c t s however, i n d u s t r y o f t e n perpetuates unfounded p e r c e p t i o n s by f l a g g i n g " a l l n a t u r a l " i n g r e d i e n t s i n a d v e r t i s i n g " (p64, S t i l l i n g , 1980). A 1978 survey of Vancouver H e a l t h food u s ers found that 3 most of those shoppers surveyed were l e a s t able of a f f o r d the s p e c i a l t y foods (Duffek,1978). Another survey showed that these h e a l t h food products were 30 % to 100% higher i n cost than the same foods i n a r e g u l a r grocery s t o r e (Annon., 1973). A d d i t i o n a l surveys i n d i c a t e t h at consumers are very i n t e r e s t e d i n o b t a i n i n g more i n f o r m a t i o n about food a d d i t i v e s (Knox and Schreiber,1980; Boocock, 1978; Z i b r i c k et a l , 1981). However, i t i s t h i s very lack of i n f o r m a t i o n that renders consumers s u s c e p t i b l e to m i s i n f o r m a t i o n due to d i f f i c u l t i e s i n a s s e s s i n g the r e l i a b i l i t y of incoming i n f o r m a t i o n (Hall,1977; C l y d e s d a l e , 1980; Harper, 1979). C l y d e s d a l e (1980) suggests t h a t when value judgements are made about food, the wariness t h a t ensues i s due to emotions and lac k of understanding, not wariness based on the c a p a b i l i t i e s of making sound judgements based on a p p r o p r i a t e i n f o r m a t i o n . T h e r e f o r e , i t i s i n the i n t e r e s t s of a w e l l - i n f o r m e d consumer that the s c i e n t i f i c community, p a r t i c u l a r l y food s c i e n t i s t s attempt to e x p l a i n c o n t r o v e r s i a l food i s s u e s i n an understandable manner. A q u e s t i o n a r i s e s however, as to the acceptance of the r e l i a b l e i n f o r m a t i o n , designed to c o u n t e r a c t the m i s i n f o r m a t i o n . How w i l l the p u b l i c accept i n f o r m a t i o n that i s i n o p p o s i t i o n to the c u r r e n t s o c i e t a l s t e r e o t y p e : "Food a d d i t i v e s are bad". ? Attempts to overcome f o o d - r e l a t e d m i s i n f o r m a t i o n suggest that there may be an i n a b i l i t y of some members of the p u b l i c to accept r e l i a b l e i n f o r m a t i o n due to i n g r a i n e d food b e l i e f s . (Anderson and Standal,1976). T h i s i s supported by Saegert and 4 Saegert (1976), who f e l t t h a t some people may be so tuned i n t o food fad cl a i m s that they may be h i g h l y r e s i s t a n t to any e d u c a t i o n a l e f f o r t t h a t i s p e r c e i v e d to o r i g i n a t e from the es t a b l i s h m e n t . Sims (1976) found that there appeared to be a great d e a l of i n f l u e n c e on consumer a t t i t u d e s from p r i v a t e sources of i n f o r m a t i o n that represented unreputable i n f o r m a t i o n . Based on t h i s , Saegert and Saegert (1976) suggest that the issue of e f f e c t i v e consumer education would appear to be r e l a t e d to the t r a d i t i o n a l a t t i t u d e change v a r i a b l e of source c r e d i b i l i t y . I. THE GENERAL PROBLEM The general purpose of t h i s study was to shed some l i g h t on how to communicate to the p u b l i c a message which was c o n t r a r y to popular b e l i e f s . S o c i e t a l s t e r e o t y p e s tend t o be r e s i s t a n t to change and, consequently, any attempt to co u n t e r a c t the ste r e o t y p e through v e r b a l communication must c o n s i d e r problems such as those which f o l l o w . I I . SPECIFIC PROBLEMS The s p e c i f i c problems addressed by t h i s study concern the accceptance of a message designed to co u n t e r a c t the mi s i n f o r m a t i o n about food a d d i t i v e s with r e l i a b l e i n f o r m a t i o n from experts i n t h i s f i e l d . Among many food t o p i c s , the food a d d i t i v e i s s u e was chosen because of the documented problem that e x i s t s r e g a r d i n g consumer p e r s p e c t i v e s on food a d d i t i v e s ; the demonstrated need f o r r e l i a b l e i n f o r m a t i o n ; the unknown e f f e c t of an expert d i s s e m i n a t i n g i n f o r m a t i o n that i s c o n t r a r y to what many consumers b e l i e v e ; and i n t e r e s t on the pa r t of the 5 r e s e a r c h e r i n meeting the need f o r r e l i a b l e i n f o r m a t i o n . S e v e r a l q u e s t i o n s were r a i s e d as to the e f f e c t i v e n e s s of a knowledgeable p r o f e s s i o n a l p r o v i d i n g i n f o r m a t i o n that was counter to the general b e l i e f s and a t t i t u d e s among consumers. 1) Who are the most c r e d i b l e sources of i n f o r m a t i o n on food a d d i t i v e s ? I t would be of i n t e r e s t t o know what sources are p e r c e i v e d to be the most c r e d i b l e so that they may be u t i l i z e d f o r d i s s e m i n a t i o n of r e l i a b l e i n f o r m a t i o n . 2) Does the source of r e l i a b l e i n f o r m a t i o n i n f l u e n c e b e l i e f i n a pro-food a d d i t i v e message ? Research r e s u l t s say yes. According to Hovland (1953), Osgood et a l . (1957), McCroskey and Young (1981), McGuire (1969), Hass (1980), F i s h b e i n and Ajzen (1981), and o t h e r s , the p e r c e i v e d competence and c h a r a c t e r of the message source w i l l i n f l u e n c e the b e l i e f i n or acceptance of a message. I t i s not yet known i f the source i s s i g n i f i c a n t i n terms of a pro-food a d d i t i v e message. Perhaps the viewpoint of the message i t s e l f i s a more important f a c t o r when the issue being addressed l i e s i n a s e n s i t i v e area and when th e r e i s a r a t h e r s t r o n g popular b e l i e f about the i s s u e . 3) Does a person's i n i t i a l a t t i t u d e toward food a d d i t i v e s i n f l u e n c e t h e i r b e l i e f i n a pro-food a d d i t i v e message? The d i s c r e p a n c y of the message viewpoint from that of the r e c e i v e r has been shown to i n f l u e n c e the b e l i e v a b i l i t y of the message. In a d d i t i o n , message d i s c r e p a n c y w i l l i n f l u e n c e the 6 e f f e c t of source c r e d i b i l i t y (an i n t e r a c t i o n e f f e c t ) (Hass, 1981). I t was c o n s i d e r e d u s e f u l to determine what the e f f e c t i s with a pro-food a d d i t i v e message a t t r i b u t e d to h i g h l y c r e d i b l e sources. I I I . DEFINTIONS A number of terms have been used i n t h i s study that are c h a r a c t e r i s t i c of the f i e l d of s o c i a l psychology and communications. For c l a r i f i c a t i o n , they are d e f i n e d here. I. SOURCE CREDIBILTY For the purpose of t h i s study, source c r e d i b i l i t y i s d e f i n e d as the a t t i t u d e toward a source of a communication h e l d at a given time by a r e c e i v e r (Tubbs and Moss, 1980). T h i s a t t i t u d e has two dimensions: the p e r c e i v e d competence and the p e r c e i v e d c h a r a c t e r of the source h e l d by the r e c i e v e r of the communication (McCroskey and Young, 1980). A source i s h i g h l y c r e d i b l e when p e r c e i v e d to be h i g h l y competent and to possess a good c h a r a c t e r . I I . ATTITUDE A t t i t u d e i s a l e a r n e d p r e d i s p o s t i o n to respond i n a c o n s i s t e n t l y f a v o u r a b l e or unfavourable manner with respect to a given o b j e c t . The three b a s i c f e a t u r e s of a t t i t u d e are a) that i t i s l e a r n e d , b) that i t p r e d i s p o s e s a c t i o n and thereby a c t s as an u n d e r l y i n g guide to i n f l u e n c i n g behavior, and c) i t has an u n d e r l y i n g e v a l u a t i v e dimension r e q u i r i n g f a v o u r a b l e or unfavourable judgement. ( F i s h b e i n and Ajzen, 1981) 7 I I I . BELIEF B e l i e f s represent the i n f o r m a t i o n a person has about an o b j e c t . B e l i e f l i n k s an o b j e c t , such as a person, group or i n s t i t u t i o n or p o l i c y or event to an a t t r i b u t e , such as an o b j e c t , t r a i t , p r o p e r t y , q u a l i t y , or c h a r a c t e r i s t i c outcome. People d i f f e r i n the s t r e n g t h of t h e i r b e l i e f s , t h a t i s , i n the p e r c e i v e d l i k l i h o o d t h a t the o b j e c t i s a s s o c i a t e d with the a t t r i b u t e i n q u e s t i o n . Thus, the u n d e r l y i n g dimension of b e l i e f i s a p r o b a b i l i t y dimension, r a t h e r than an e v a l u a t i v e or judgemental one ( F i s h b e i n and Azjen, 1975). IV. DIMENSION The dimension of a c o n s t r u c t i s a l a t e n t t r a i t or a t t r i b u t e assumed to underly the c o n s t r u c t . For example, an e v a l u a t i v e dimension i s assumed to u n d e r l i e a t t i t u d e toward an o b j e c t . V. CONSTRUCT A c o n t s r u c t i s a d e f i n e a b l e idea or phenomena. For example, source c r e d i b i l i t y i s a c o n s t r u c t . VI. CONNOTATIVE/DENOTATIVE A statement i s s a i d to be c o n n o t a t i v e i f i t e l i c i t s an a f f e c t i v e response , such as ' e v a l u a t i o n ' , i n a t t i t u d e measurement. A d e n o t a t i v e statement i s a f a c t u a l statement. In measuring a t t i t u d e i t i s important that the b e l i e f statements used f o r t h i s purpose are not d e n o t a t i v e . Instead, the statements should e l i c i t a f a v o u r a b l e or unfavourable e v a l u a t i v e response toward the a t t i t u d e o b j e c t i n the statement. A l s o , the 8 a d j e c t i v e p a i r s used i n the measurement s c a l e s should be co n n o t a t i v e r a t h e r than d e n o t a t i v e . IV. RESEARCH HYPOTHESES Based on the s p e c i f i c problems, the f o l l o w i n g r e s e a r c h h y p o thesis were i n v e s t i g a t e d . Corresponding s t a t i s t i c a l hypotheses were formulated and analyzed i n Chapter 4, R e s u l t s . 1) I f the s u b j e c t s r e c e i v e a r e l i a b l e pro-food a d d i t i v e message from a c r e d i b l e source, then b e l i e f i n the message w i l l be i n f l u e n c e d to a s i g n i f i c a n t degree by the message source. 2) I f a subj e c t r e c e i v e s a pro-food a d d i t i v e message, then, b e l i e f i n the message w i l l depend to a s i g n i f i c a n t degree on the s u b j e c t ' s i n i t i a l a t t i t u d e toward food a d d i t i v e s . 3) I f a su b j e c t r e c e i v e s a pro-food a d d i t i v e message, then b e l i e f i n the message w i l l depend to a s i g n i f i g a n t degree on the i n t e r a c t i o n between the s u b j e c t ' s i n i t i a l a t t i t u d e and the source of the message. 9 V. METHOD OF STUDY I. POPULATION The t a r g e t p o p u l a t i o n of any r e l i a b l e i n f o r m a t i o n would be the "average" consumer who makes food c h o i c e s i n the market p l a c e . I I . THE SAMPLE The sample p o p u l a t i o n used i n t h i s study c o n s i s t e d of a r e a d i l y a c c e s s i b l e group of summer students e n r o l l e d i n Education Psychology courses at the U n i v e r s i t y of B r i t i s h Columbia. Most were te a c h e r s , with ages ranging from 25 to 45 (ap p r o x i m a t e l y ) . Because of t h e i r p r o f e s s i o n s , t h i s sample may be of higher than average educa t i o n , and perhaps higher than average socio/economic background. The sample used was a sample of convenience. I I I . INSTRUMENTS USED i . Presurvey _1_ The f i r s t presurvey i n v o l v e d a q u e s t i o n a i r e to determine which of nine p o s s i b l e sources of i n f o r m a t i o n about food a d d i t i v e s were p e r c e i v e d to be the most c r e d i b l e . The survey i n v o l v e d responses on s i x 7-point s c a l e s , anchored by b i - p o l a r a d j e c t i v e p a i r s that measured c r e d i b i l i t y . (McCoskey and Young, 1980) The surveys were conducted with a random sampling of vol u n t e e r students w i t h i n the Department of Food Science at UBC. 1 0 i i . Presurvey 2 The second presurvey determined what statements should be used i n the a t t i t u d e measure of the main survey. Twenty-two p o s s i b l e statements, generated from the l i t e r a t u r e and expert o p i n i o n , were assessed by respondents who i n d i c a t e d on a 7 - p o i n t s c a l e how s t r o n g l y p o s i t i v e or how s t r o n g l y negative the statement was f e l t to be. A random sampling of v o l u n t e e r students w i t h i n the Department of Food Science at The U n i v e r s i t y of B r i t i s h Columbia completed the survey. On the b a s i s of the scor e s , (highest and lowest s i x ) , a t o t a l of s i x statements were chosen on the b a s i s of t h e i r extremeness of p o l a r i t y ( p o s i t v e or negative) and the standard d e v i a t i o n of the s c o r e s . A n a l y s i s of the measurement instrument was conducted v i a the LERTAP computer programme. The program generated both d e s c r i p t i v e and i n f e r e n t i a l s t a t i s t i c s f o r the purpose of determining the l o p e r a t i n g c h a r a c t e r i s t i c s of the items ( a d j e c t i v e p a i r s ) and the o v e r a l l t e s t . A l s o c a l c u l a t e d were the mean scores f o r b e l i e f and a t t i t u d e , as w e l l as i n d i v i d u a l s c o r e s . i i i . Main Survey The main survey c o n s i s t e d of a booklet comprised of the a t t i t u d e and b e l i e f measure, the pro-food a d d i t i v e message a t t r i b u t e d to a source and a measure of b e l i e f i n the message. The a t t i t u d e and b e l i e f measure was made us i n g the s i x food a d d i t i v e statements chosen from Presurvey Two, with three pro-food a d d i t i v e s and three a n t i - f o o d a d d i t i v e s . F o l l o w i n g each 11 statement was a set of 8 b i - p o l a r a d j e c t i v e p a i r s , anchoring 7-p o i n t s c a l e s . The f i r s t four a d j e c t i v e p a i r s measured b e l i e f in the statement ,the c o v a r i a t e . These a d j e c t i v e s were: t r u e -f a l s e , l i k e l y - u n l i k e l y , probable- improbable and impossible-p o s s i b l e . The l a s t four a d j e c t i v e p a i r s measured a t t i t u d e , the a t t r i b u t e v a r i a b l e , by responses t o : w i s e - f o o l i s h , s i c k - h e a l t h y , good- bad, and h a r m f u l - b e n i f i c i a l ( F i s h b e i n and Raven, 1967). Then followed a pro-food a d d i t i v e message a t t r i b u t e d to one of the three most c r e d i b l e sources as determined i n Presurvey One, or to no source at a l l . There were t h e r e f o r e four groups of q u e s t i o n a i r e s , each with the same message a t t r i b u t e d to d i f f e r e n t sources. The q u e s t i o n a i r e s were randomly d i s t r i b u t e d among the sample p o p u l a t i o n . VI. ANALYSIS OF RESULTS R e s u l t s were assessed u s i n g l i n e a r m u l t i p l e r e g r e s s i o n a n a l y s i s i n v o l v i n g both continuous v a r i a b l e s ( b e l i e f i n statements and a t t i t u d e toward food a d d i t i v e s ) and c a t e g o r i c a l v a r i a b l e s ( treatments i e . the sources of the message). The UBC BMD:03R computer programme was used to analyze the d ata. V I I . LIMITATIONS There may be some d i f f i c u l t y with g e n e r a l i z a t i o n of the Presurvey One r e s u l t s to those of the Main Survey due to the f a c t t h a t people with a food s c i e n c e baround completed the two p resurveys, while education psychology students completed the main survey. In the p r e p a r a t i o n of the booklet and the v e r b a l i n s t r u c t i o n s there was no attempt made to hide the purpose of 12 the study. Because respondents knew the purpose of the survey, i e . , that the e f f e c t of message source was being s t u d i e d , t h e i r responses may have been b i a s e d , f o r example, to please the re s e a r c h e r . A convenient sample was used and t h i s makes e x t r a p o l a t i o n of the r e s u l t s to the general p u b l i c , f o r whom t h i s i n f o r m a t i o n would be u s e f u l , p r o b l e m a t i c . Time, f i n a n c i a l c o n s t r a i n t s and a v a i l a b i l i t y of s u b j e c t s f o r the study d i c t a t e d t h i s d e c i s i o n . I d e a l l y there should be 30 or more s u b j e c t s f o r each v a r i a b l e measured. With two treatment v a r i b l e s ( a t t i t u d e and b e l i e f i n statements), one dependent v a r i a b l e and four treatment v a r i a b l e s , 7 x 30 =210 s u b j e c t s should have been u t i l i z e d . U n f o r t u n a t e l y , the sample s i z e was 125, and so care should be taken i n e x t r a p o l a t i o n of r e s u l t s . In one of the c l a s s e s some feedback was obtained r e g a r d i n g the survey. The a s s o c i a t i o n of some of the sources to the message was deemed u n r e a l i s t i c by some. i e . , "a doctor would never say anything l i k e t h i s " . V I I I . SAFEGUARDS To minimize s e r i o u s e f f e c t s on the survey due to a d m i n i s t r a t i o n of the t e s t , the re s e a r c h e r s t a n d a r d i z e d the i n s t r u c t i o n s and c o n d i t i o n s as c a r e f u l l y as p o s s i b l e . For example, the same i n s t r u c t i o n s were read v e r b a l l y to each c l a s s . Care was a l s o taken to reduce b i a s i n the response. To i l l u s t r a t e , the b i p o l a r a d j e c t i v e s on the s c a l e s were re v e r s e d so that a l l the favo u r a b l e a d j e c t i v e s would not be down the l e f t s i d e of the page. T h i s was done to dis c o u r a g e l a z y responses 13 and to a v o i d what i s sometimes r e f e r r e d to as 'space e r r o r ' . ( F i s h b e i n and Raven, 1975) The s c a l e s were p r e v i o u s l y assessed to be r e l i a b l e ( F i s h b e i n and Raven, 1967). Standard e r r o r s and Hoyt R e l i a b l i t y C o e f f i c i e n t s o b t a i n e d met the r e l i a b i l i t y c r i t e r i a o u t l i n e d by Nelson (1977). An attempt to ensure v a l i d i t y c o n s i s t e d of input by experts who evaluated the statements that were used i n the measure, and the s t r u c t u r e of the message. 14 I I . LITERATURE REVIEW I. BACKGROUND TO THE PROBLEM I t i s widely supported i n the l i t e r a t u r e t h a t there i s a concern among consumers about the s a f e t y and adequacy of the food supply,and i n p a r t i c u l a r , the s a f e t y of food a d d i t i v e s d e s p i t e a l a c k of suppoting s c i e n t i f i c evidence f o r the concern (Annon., 1973; Bates,1981; Bruch,l970; Duffek,l978; Hall,1973; Hopper,1977; Boocock, 1978; S t i l l i n g s , 1 9 8 0 ; Trenholm, 1980; Zi b r i c k , 1 9 8 1 ; Knox and S c h r e i b e r , 1980). These concerns have l e a d to the avoidance of processed foods and a d d i t i v e s by some consumers and to the use of " h e a l t h foods", "organic foods" and " n a t u r a l foods" . I t i s p o s s i b l e that these tendencies are a "food f a d " , d e f i n e d as" favored or popular p u r s u i t s or f a s h i o n s i n food consumption, p r e v a i l i n g f o r a p e r i o d of time " (Bruch, 1970). There are three b a s i c types of food fads: 1) those where s p e c i a l v i r t u e s of a p a r t i c u l a r food are exaggerated and are purported to cure s p e c i f i c d i s e a s e s ; 2) those where c e r t a i n foods are e l i m i n a t e d from the d i e t due to the b e l i e f t h a t harmful elements are present; 3) those where the emphasis i s p l a c e d on" n a t u r a l " foods. 15 Concerns about food a d d i t i v e s that l e a d to t h e i r e l i m i n a t i o n from the d i e t c o u l d be c a t e g o r i z e d as a type 2) f a d : avoidance of foods b e l i e v e d to c o n t a i n harmful elements. T h i s c o u l d q u i t e p o s s i b l y l e a d to type 3) fad, the use of " n a t u r a l " foods. As l i s t e d i n Chapter 1, (page 1), there are many s p e c i f i c misconceptions about food a d d i t i v e s that h e l p support the " f a d " . Reasons f o r the misconceptions can be c l a s s i f i e d i n t o the f o l l o w i n g . c a t e g o r i e s : 1) s o c i o l o g i c a l 2) emotional 3) p s y c h o l o g i c a l 4) p o p u l a r i t y of m i s i n f o r m a t i o n 5) l a c k of r e l i a b l e i n f o r m a t i o n 6) e d u c a t i o n a l 7) p o l i t i c a l / g o v e r n m e n t a l I. SOCIOLOGICAL Cly d e s d a l e suggests a s o c i o l o g i c a l e x p l a i n a t i o n f o r the misconceptions about food a d d i t i v e s a f e t y . A f a s t - p a c e d world, b e w i l d e r i n g and f r u s t r a t i n g l i f e s t y l e s coupled with a m i s t r u s t of b i g business has l e d to a d e s i r e f o r a simpler, slower moving, honest and b a s i c l i f e s t y l e (Hall,1977; Clydesdale,1980) Since food companies represent b i g business and and food a d d i t i v e s a modern p r o d u c t i o n system that i s a l l p a r t of a complicated and c o n f u s i n g modern l i f e s t y l e , food a d d i t i v e s are r e j e c t e d . H a l l (1977) r e f e r s to the complexity and m a t e r i a l i s m 16 of modern s o c i e t y . Hopper (1977) s t a t e s that a lack of understanding of a complex s c i e n t i f i c world has caused a backward step i n understanding. Young and S t i t t (1981) say that the back to nature t r e n d i s a s t e p to c o u n t e r a c t the problems of c i v i l i z a t i o n . S e v e r a l authors make ref e r e n c e to the r i t u a l c u l t or r e l i g i o u s a s p e c t s of adherence to a l t e r n a t i v e d i e t s , such as Zen M a c r o b i o t i c , that exclude processed foods and food a d d i t i v e s (Bates, 1981; B i t e n s t k y , 1973; Annon.,1973). Another aspect of s o c i o l o g i c a l causes of concerns about food i s that i n times of food a f f l u e n c e (as the p r e s e n t ) , there i s no need to worry about s t a r v a t i o n . The worry about food, p a r t of the b a s i c human s u r v i v a l i n s t i n c t , has now s h i f t e d to the s a f e t y and adequacy of food (Bates, 1981) and to the s p e c i f i c b e n i f i t s from p a r t i c u l a r foods ( C l y d e s d a l e , 1980). I I . EMOTIONAL Cl y d e s d a l e (1980), e x p l a i n s that the emotional aspects of food consumption, p a r t i c u l a r l y the intimacy i n v o l v e d , causes good or bad v a l u e s to be p l a c e d on the food i t s e l f . Indeed, the sense of w e l l - b e i n g a s s o c i a t e d with e a t i n g the " r i g h t " kind of food causes that food to become a p a c i f i e r , a g i v e r of contentment and repose (Boocock, 1978; Bruch, 1970). In a d d i t i o n , e a t i n g i s much more than a matter of appeasing hunger. The c u l t u r a l , moral, and s o c i a l involvement that d i c t a t e s what we ea t , when we eat, how we e a t , and with whom we eat makes food consumption i t s e l f very emotional (Bruch, 1970; H a l l , 1977; C l y d e s d a l e , 1980). 17 I I I . PSYCHOLOGICAL The psychology of the problems of misocnceptions about food i s d e a l t with by s e v e r a l a u t h o r s . Bruch (1970), suggests that " . . . . i f e a r l y p e r s o n a l experiences are unwholesome, i n s t e a d of developing a b a s i c t r u s t , an i n d i v i d u a l becomes deeply m i s t r u s t i n g ; views l i f e s i t u a t i o n s as t h r e a t e n i n g ; some develop r i g i d p e r s o n a l i t i e s and r e p r e s s the impulse to experience s a t i s f a c t i o n ; d i s c h a r g e s r e p r e s s e d h o s t i l i t y at a convenient c u l t u r a l scapegoat. For these people, s e c u r i t y i s equal to p u r i t y and h e a l t h i s equal to n a t u r a l n e s s . Food a d d i t i v e s are p e r c e i v e d to represent a d u l t e r a t e d , s y n t h e t i c food - something to be avoided. T h i s person i s concerned with pure food, pure morals, and pure r a c e s . He sees s a f e t y i n the o l d and f a m i l i a r , while the new and u n f a m i l i a r ( l i k e food a d d i t i v e s ) i s viewed with s u s p i c i o n and apprehension as t h r e a t e n i n g . " (p.318). I t i s u n l i k e l y that the vast m a j o r i t y of consumers w i l l f a l l i n t o t h i s category. However,those that do h e l p to perpetuate the m i s i n f o r m a t i o n . There are s e v e r a l other s i t u a t i o n s i n which psychology p l a y s a r o l e i n misconceptions about food: 1) There i s a p s y c h o l o g i c a l need f o r the c h r o n i c a l l y i l l t o s o l v e h e a l t h problems that are unsolveable by t r a d i t i o n a l medicine. The need f o r hope i s met by p a r t i c u l a r d i e t or supplement regimes. These food fad adherents have been r e f f e r e d to as ' m i r a c l e - s e e k e r s ' , with u n c r i t i c a l b e l i e f s i n b i z a r r e and u n r e a l i s t i c promises. (Bruch, 1970; Annon., 1973). 2) Some people are a f r a i d and anxious r e g a r d i n g the u n c e r t a i n t i e s and t h r e a t s of l i v i n g and become overconcerned about t h e i r h e a l t h (Bruch, 1970). 3) S u s c e p t a b i l i t y to food fadism has been shown to be a s s o c i a t e d with b i z a r r e or e x t r e m i s t p e r s o n a l i t y t r a i t s r e s u l t i n g i n i r r a t i o n a l behaviour.People use a product in the absence of c l e a r - c u t harmful p r o p e r t i e s j u s t to be sure" (McBean and Speckman, 1974). 4) A d d i t i o n a l p s y c h o l o g i c a l d e s c r i p t o r s i n c l u d e p a r a n o i c s or e x t r e m i s t s with a desperate m i s t r u s t of the medical p r o f e s s i o n , t r u t h - s e e k e r s , f a s h i o n f o l l o w e r s , s u p e r - h e a l t h pursuants, and r i t u a l or a u t h o r i t y - s e e k e r s (Bruch, 1970; Annon., 1973). 5) These d e s c r i p t o r s are very g e n e r a l i z e d over a wide range of food behaviours. In a study to determine the v a r i a b l e s a s s o c i a t e d wth the consumption of food fad p r o d u c t s , v i t a m i n E users were found not to be more n e u r o t i c a l l y anxious or s o c i a l l y a b r a i s i v e and had no more a n t i e s t a b l i s h m e n t views than non-users of v i t a m i n E. They were, however, l e s s ego-o r g a n i z e d and more e x t r o v e r t e d and 19 r e l a t i v e l y more unstable and i m p r a c t i c a l , which suggests s u s c e p t i b i l i t y t o unsupported c l a i m s made f o r fad h e a l t h products (Saegert & Saegert, 1976). 6) In another study, psychotism and n e u r o t i c i s m of c o l l e g e students was compared to t h e i r food c h o i c e s and no c o r r e l a t i o n was found ( L e s t e r , 1979). IV. MISINFORMATION M i s i n f o r m a t i o n , whether i n t e n t i o n a l ( f o r econimic gain v i a promotion of a book or produt) or u n i n t e n t i o n a l (by misguided, but w e l l - i n t e n t i o n e d i n d i v i d u a l s or groups) i s popular because the r a t i o n a l s c i e n t i f i c approach f a i l s to f u l f i l the d e s i r e a b l e needs "of s u f f e r i n g people who want to be made b e t t e r by t h e i r food ( F r a n c i s , 1979). In a d d i t i o n , the f i e l d of food and n u t r i t i o n i s p a r t i c u l a r l y open to quacks and c u l t i s t s who f i l l t h i s emotional gap f o r hope that t r a d i t i o n a l h e a l t h and food education n e g l e c t s ( F r a n c i s , 1979; S t i l l i n g s , 1980; Bruch, 1970). U n f o r t u n a t e l y , the p u b l i c does not posess the s k i l l s and knowledge r e q u i r e d to d i f f e r e n t i a t e between f a c t and f a l l a c y (Annon., 1973). Freedom of the p r e s s means that i n f o r m a t i o n , r e g a r d l e s s of i t s s c i e n t i f i c v e r a c i t y can be p u b l i s h e d . The B r i t i s h Columbia N u t r i t i o n C o u n c i l (1978) l i s t s the f o l l o w i n g c r i t e r i a f o r c o n s i d e r i n g p a r t i c u l a r food and n u t r i t i o n books to be u n r e l i a b l e : 20 1) the focus i s on magical and c u r a t i v e powers of a s p e c i f i c n u t r i e n t or food or the avoidance of such; and the c l a i m s are exaggerated o f t e n to promote a s p e c i a l product. At times the reccommendations ar e dangerous to h e a l t h ; 2) quotes from n u t r i t i o n experts or r e s e a r c h r e s u l t s are o f t e n d i s t o r t e d and used out of context to s u i t the author's purpose; 3) n u t r i t i o n a l recommendations are o f t e n based on a n e c d o t a l expriences or p e r s o n a l hunches and t h e r e f o r e l a c k the o b j e c t i v i t y of s c i e n t i f i c r e s e a r c h ; 4) o v e r a l l c o r r u p t i o n of the s c i e n t i f i c and medical establishment i s suggested and exagerated f e a r t a c t i c s are sometimes used to arouse f e a r of normal food. S i m i l a r problems are encountered with the popular i n f o r m a t i o n on food a d d i t i v e s . In the media (newspapers, magazines, r a d i o , t e l e v i s i o n ), a tendancy to p o l a r i z e i s s u e s i n t o black and white, good and bad, has l e d to a s e n s a t i o n a l i z e d p i c t u r e of food a d d i t i v e s . The r e p o r t e r may have d i f f i c u l t y i n a s s e s s i n g the s c i e n t i f i c a s p e c t s of the r e s e a r c h , or, have a p a r t i c u l a r b i a s or p o i n t of view to convey. C l y d e s d a l e (1980) s t a t e s that there i s a tendancy t o d i s t o r t both the advantages and l i m i t a t i o n s of s c i e n c e to accomplish or prove a p o i n t of view. T h i s leads to 21 d i s t o r t i o n of the a c t u a l f a c t s and i n f o r m a t i o n (Clydesdale, 1980). The media has been accused of m i s l e a d i n g r e p o r t i n g , ( L e v e i l l e , 1980) and s e n s a t i o n a l i z i n g food i s s u e s (Harper, 1979; H a l l , 1973; Sloan,1981). An example, o u t l i n e d by Sloan (1981) r e v e a l e d an i n c i d e n t i n which the r e s u l t s of an experiment demonstrated only that 10- 20% of carbohydrate i n wheat f l o u r was not absorbed. T h i s was d i s t o r t e d to such h e a d l i n e s as "Study Shows White F l o u r i s D i g e s t i v e V i l l a i n ". H a l l (1973) says that the media emphasizes bad news s i n c e i t s e l l s much b e t t e r than good news . Hence the image of food that i s the outcome of the r e p o r t i n g on food i s s u e s i s a bad one. M a r s h a l l (1979), e x p l a i n s f u r t h e r that r e p o r t e r s tend to search out opp o s i t e p o l e s of o p i n i o n and then balance one extreme a g a i n s t the other to c r e a t e an a r t i f i c i a l form of o b j e c t i v i t y . But, the middle ground i s l e f t i g n o r e d . He goes on t o say that a l s o , there i s an i n a b i l i t y of newspapers to understand the s u b t l t i e s of s c i e n t i f i c debate. V. LACK OF RELIABLE INFORMATION The lack of r e l i a b l e i n f o r m a t i o n a v a i l a b l e t o consumers i s due to s e v e r a l reasons. Food companies, the users of food a d d i t i v e s , do r e l a t i v e l y l i t t l e to educate consumers about food i n g r e d i e n t s . What i n f o r m a t i o n that does come acro s s o f t e n s p i l l s over from promotional a c t i v i t i e s and t h e r e f o r e l a c k s c r e d i b i l i t y ( H a l l , 1973). In a d d i t i o n , the more recent t r e n d of the i n d u s t r y to jump on the " a l l n a t u r a l " bandwagon does l i t t l e to i n s t i l l c o n f i d e n c e i n the o r i g i n a l products ( Hall,1973; S t i l l i n g s , 1 9 8 0 ; Hopper, 2 2 1977; C l y d e s d a l e , 1980). Another problem that reduces the amount of r e l i a b l e i n f o r m a t i o n i s that p r o f e s s i o n a l s are o f t e n poor communicators, d e s p i t e the f a c t t h at they are p e r c e i v e d to be h i g h l y c r e d i b l e ( H a l l , 1973; Hopper, 1977; Annon.,1973; Omnibus surveys, 1981...check) There i s a need f o r e t h i c a l , d i s c i p l i n e d s c i e n i s t s who don't jump the gun on r e l e a s i n g r e s u l t s to the media and are prepared to e x p l a i n the s i g n i f i c a n c e of t h e i r work ( H a l l , 1973). I t i s unfortunate that a l l the answers to some of the food i s s u e s are not a v a i l a b l e . T h i s makes i t d i f f i c u l t to give one a b s o l u t e unequivocal answer ( C l y d e s d a l e , 1980; Celender & Sloan, 1977). Issues are l e f t open f o r s e l f - a p p o i n t e d a d v i s o r s to p r o v i d e easy answers. The r e l a t i o n s h i p between d i e t and c h r o n i c d egenerative d i s e a s e s i s p a r t i c u l a r l y v u l n e r a b l e to t h i s s o r t of t h i n g ( L e v e i l l e , 1 9 8 1 ) . VI. EDUCATIONAL There i s a d i f f i c u l t y i n the e d u c a t i o n a l process i t s e l f t hat has l e a d to misunderstandings about food i s s u e s . T e c h n i c a l i s s u e s are o f t e n so complex that e d u c a t i o n a l e f f o r t s have lagged behind, p a r t i c u l a r l y i n the area of r i s k a s s o c i a t e d with food consumption ( F r a n c i s , 1979). Increased i n d u s t r i a l i z a t i o n and technology make i t d i f f i c u l t f o r consumers to use t h e i r own judgement reg a r d i n g the u t i l i t y and s a f e t y of food (Celender & Sloan, 1977; H a l l , 1977). Another author s t a t e s that the h o s t i l i t y index f e l t by consumers toward processed foods i s d i r e c t l y c o r r e l a t e d with the degree of ignorance r e g a r d i n g food, though t h i s has yet to be shown (Boocock, 1978). Hopper (1977) 2 3 agrees that a lack of knowledge, p l u s m i s i n f o r m a t i o n have l e a d to an e r r o d i n g confidence i n the food supply. There i s an ignorance of food composition ( C l y d e s d a l e , 1980), that has le a d to a "chemophobia" paranoia about any ch e m i c a l - sounding i n g r e d i e n t s ( F r a n c i s , 1979). Sev e r a l authors agree that there i s a gen e r a l l a c k of understanding of the process of s c i e n t i f i c enquirey (Harper, 1977; M a r s h a l l , 1979; C l y d e s d a l e , 1981). The u n r e a l i s t i c e x p e c t a t i o n i s p l a c e d on s c i e n c e and technology to e x p l a i n occurrances i n a l l circumstances t h a t which i s researched only i n p a r t i c u l a r given c i r c u m s t a n c e s . T h i s r e s u l t s i n e x t r a p o l a t i o n of r e s u l t s to a g e n e r a l , all-encompassing s i t u a t i o n , when the r e s u l t s apply t o one s i t u a t i o n o n l y . V I I . POLITICAL/GOVERNMENTAL P o l i t i c s and the government can be blamed f o r pa r t of the problem of food m i s i n f o r m a t i o n . S e v e r a l governmental a g e n i c i e s are i n v o l v e d with food a d d i t i v e s , p a r t i c u l a r l y the H e a l t h P r o t e c t i o n Branch (HPB) of H e a l t h and Welfare Canada and Consumer and Corporate A f f a i r s (CCA). The HPB governs the use of food a d d i t i v e s and s a f e t y e v a l u a t i o n . T h i s p r o t e c t i o n has been i n t e r p r e t e d by the p u b l i c to mean that there i s no r i s k a s s o c i a t e d with food consumption. F r a n c i s (1979) s t a t e s that i t i s a shock f o r the p u b l i c to l e a r n that there i s no a b s o l u t e s a f e t y concerning food. T h i s causes a backlash of a v o i d i n g foods thought to be " r i s k y " , when they are found not to be 100% beyond a doubt s a f e . Yet, i n the world, nothing i s a b s o l u t e l y , s a f e . Even n a t u r a l hazards, such as t o x i n s from b a c t e r i a or 24 mould, can be of more s i g n i f i c a n t r i s k to h e a l t h than a d d i t i v e s ( H a l l , 1973, 1977). The banning of a food a d d i t i v e causes many r e p e r c u s s i o n s . Eroding confidence i n governments who appear d e r e l i c t i n t h e i r duty to p r o t e c t ; a food i n d u s t r y c a l l u s i n t h e i r r e s p o n s i b i l i t y to produce safe products; and consumer exposure to needless hazard while the a d d i t i v e i s t e s t e d , are a l l s i d e e f f e c t s of banning a food a d d i t i v e once c o n s i d e r e d s a f e (Hopper, 1977). In a c t u a l f a c t , however, d e l i s t i n g of a food a d d i t i v e i s a response to an i n c r e a s e i n world body of knowledge, improved measurement techniques and an expert assessment of the r i s k s vs the b e n i f i t of use. In other words, the f i l e i s not c l o s e d once an a d d i t i v e i s approved - s c i e n c e marches on seeking f u r t h e r knowledge. L e g i s l a t i v e d e c i s i o n s to ban a food a d d i t i v e may be taken as r e p r e s e n t i n g f a c t u a l r i s k s , when they represent only concensus and compromise that uses the s c i e n t i f i c i n f o r m a t i o n , but, not s c i e n t i f i c method ( L e v e i l l e , 1980). In summary, the problem of m i s i n f o r m a t i o n and food fads i s w e l l documented. The q u e s t i o n remains as to how to c o r r e c t the s i t u a t i o n . I I . SOURCE CREDIBILITY The idea that the source of a message c o u l d i n f l u e n c e the extent to which a r e c e i v e r b e l i e v e d what the message advocated has e x i s t e d s i n c e the time of A r i s t o t l e . A r i s t o t l e viewed ethos, another name f o r source c r e d i b i l i t y , as one of the most potent means of per s u a s i o n (McCroskey and Young, 1981). In the past s i x t y y e a r s , source c r e d i b i l i t y , a l s o c a l l e d 25 ethos, p r e s t i g e , charisma or image (Berlo et a l . , 1970), has been s t u d i e d e x t e n s i v e l y by r e s e a r c h e r s i n the f i e l d s of communication, s o c i a l psychology and psychology of a t t i t u d e s . The f o l l o w i n g l i t e r a t u r e review w i l l attempt to cover those aspects of the r e s e a r c h that d e f i n e the concept of source c r e d i b i l i t y and those s t u d i e s t h a t h e l p to i l l u m i n a t e the s p e c i f i c r o l e of source i n desseminating r e l i a b l e i n formation about food i s s u e s . Source c r e d i b i l i t y i s d e f i n e d as the a t t i t u d e toward a source of a communication h e l d at a given time by a r e c e i v e r , (McCroskey, 1972). Other r e s e a r c h e r s o f f e r v a r i a t i o n s of t h i s d e f i n i t i o n t h a t say e s s e n t i a l l y the same t h i n g (Tubbs and Moss,1980; Hass, 1981). McCroskey emphasizes that source c r e d i b i l i t y i s but a subset of a l l which i s p e r c e i v a b l e . I t s d i s t i n c t d e f i n i t i o n : an a t t i t u d e of a r e c e i v e r towards a source , d i s t i n g u i s e s source c r e d i b i l i t y from other p e r c e p t i o n s that people have of each other. D i f f e r e n c e s i n the e f f e c t i v e n e s s of a source depend on the a t t i t u d e of the r e c e i v e r towards the source. T h i s a t t i t u d e i s based on: 1) f e e l i n g s of a f f e c t i o n and admiration t h a t i l l i c i t a d e s i r e to be l i k e the source; 2) f e e l i n g s of awe and f e a r about the source; 3) f e e l i n g s of t r u s t r e g a r d i n g the knowledge and s i n c e r i t y of the source (Hovland et a l . , 1953). 26 These f e e l i n g s have been l a b e l e d as a t t r a c t i v e n e s s , power and c r e d i b i l i t y (Hass, 1981). In communication r e s e a r c h much a t t e n t i o n has focused on the c r e d i b i l i t y f a c t o r . T h i s i s perhaps due to the r e l a t i v e ease, i n a b r i e f l a b o r a t o r y s e t t i n g , of producing measureable changes i n the f a c t u a l b e l i e f s of the message r e c i p i e n t s . I t i s f a r more d i f f i c u l t to change r e c e i v e r ' s v a l u e s which would r e s u l t from v a r i a t i o n s i n the a t t r a c t i o n dimension (Hass, 1981). The power component i s probably not an everyday occurrance, but would be of i n t e r e s t with respect t o propoganda campaigns t h a t attempt change v i a t h r e a t s . A l s o , the emphasis on c r e d i b i l i t y may have grown out of the t r a d i t i o n a l use of i n f o r m a t i o n a l type communications i n a t t i t u d e r e s e a r c h (Hass, 1981). H i s t o r i c a l l y , t h i s c o n s t r u c t i n v o l v e s : 1) a source's knowledge of the su b j e c t 2) h i s or her v e r a c i t y 3) h i s or her a t t i t u d e toward the w e l l - b e i n g of the r e c e i v e r (McCroskey, 1972). I t i s important to note that these are the p e r c e p t i o n s of the r e c e i v e r of the message, reg a r d i n g the source. In other words, source c r e d i b i l i t y i s the degree to which a r e c e i v e r b e l i e v e s the source to know the c o r r e c t p o s i t i o n , and, the extent to which the source i s motivated to communicate that p o s i t i o n without b i a s (Hass, 1981). A r i s t o t l e c a l l e d the above three dimensions of source c r e d i b i l i t y i n t e l l i g e n c e , c h a r a c t e r and good w i l l (McCroskey and Young, 1981). • These dimensions are very s i m i l a r to the 27 expertness, t r u s t w o r t h i n e s s and i n t e n t i o n dimensions proposed by re s e a r c h e r s 2000 years l a t e r (Hovland et a l . , 1953). These dimensions are the aspects of the source that the r e c e i v e r e v a l u a t e s i n order to assess the c r e d i b i l i t y of the source of informat i o n . Since the method of f a c t o r a n a l y s i s became popular i n the s i x t i e s , many new dimensions of source c r e d i b i l i t y emerged. F a c t o r a n a l y s i s i s used to determine which c r i t e r i a l i s t e n e r s use as the b a s i s of t h e i r judgement of source c r e d i b i l i t y . More s p e c i f i c a l l y , i t i s one method of examining a c o r r e l a t i o n or c o v a r i a n c e matrix. The procedure searches f o r groups of v a r i a b l e s that are s i g n i f i c a n t l y c o r r e l a t e d with each other and not h i g h l y c o r r e l a t e d with other groups of v a r i a b l e s . These groups of v a r i a b l e s are c a l l e d " f a c t o r s " or "dimensions". The degree to which a given v a r i a b l e i s a s s o c i a t e d with a p a r t i c u l a r f a c t o r i s estimated by i t s " f a c t o r l o a d i n g " , a type of c o r r l e a t i o n between how w e l l the v a r i a b l e f i t s that f a c t o r (McCroskey and Young, 1979). Some of these s o - c a l l e d 'new dimensions' i n c l u d e : a) s a f e t y , q u a l i f i c a t i o n and dynamism ( B e r l o et a l 1970) ; b) a u t h o r i t a t i v e n e s s and c h a r a c t e r (McCroskey, 1966); c) o r i e n t a t i o n and charisma (Tuppen, 1974); d) competence, c h a r a c t e r , s o c i a b i l i t y , e x t r o v e r s i o n , composure (McCroskey, 1981); 28 In h i s recent review, McCroskey (1981) s t a t e s : "We b e l i e v e the c u r r e n t c o n f u s i o n i s a d i s t o r t i o n of the source c r e d i b i l i t y c o n s t r u c t which occured i n the e a r l y 1960's and has been perpetuated to the present " (p. 27, McCroskey, 1981). He concluded that i f the c o n s t r u c t of source c r e d i b i l i t y i s not c l e a r l y d e f i n e d and the re s e a r c h e r does not s t i c k to that c o n s t r u c t d e f i n i t i o n , i t i s q u i t e p o s s i b l e to o b t a i n other dimensions, besides the o r i g i n a l three of e x p e r t i s e , i n t e l l i g e n c e and i n t e n t i o n . A l s o , i f s c a l e s are added to measure f a c t o r s that have no resemblance to the o r i g i n a l l y d e f i n e d c o n s t r u c t , that c o n s t r u c t i t s e l f i s not changed. T h i r d l y , McCroskey s t a t e s that t h e o r e t i c a l l y there are three dimensions of source c r e d i b i l i t y : competence, c h a r a c t e r and i n t e n t i o n . . I m p i r i c a l l y however, these c o l l a p s e to two: competence and c h a r a c t e r . The p e r c e p t i o n of the source's i n t e n t i o n i s dependant on the p e r c e p t i o n of the source's c h a r a c t e r (McCroskey, 1981). In t h i s s e c t i o n the f o l l o w i n g aspects of source c r e d i b i l i t y r e s e a r c h w i l l be examined: 1) MAIN EFFECTS The main i n f l u e n c e of source c r e d i b i l i t y on the e f f e c t i v e n e s s of the communication. The design has been to s e l e c t or c r e a t e sources with d i f f e r e n t i n i t i a l l e v e l s of ethos, a t t r i b u t e an i d e n t i c a l message to the d i f f e r e n t sources f o r comparable audiences and to measure the d i f f e r e n c e s i n the p e r s u a s i v e e f f e c t ( u s u a l l y a t t i t u d e change). 29 2) INTERACTION EFFECTS The i n t e r a c t i o n e f f e c t s of source c r e d i b i l i t y with such other communication v a r i a b l e s as the audience and the message. 3) THEORETICAL EFFECTS There are s e v e r a l a t t i u d e t h e o r i e s that e x p l a i n the e f f e c t of source c r e d i b i l i t y on an i n d i v i d u a l b a s i s . These t h e o r i e s i n c l u d e c o g n i t i v e response theory, c o n g r u i t y theory, a t t r i b u t i o n theory, c o g n i t i v e dissonance dissonance theory, l e a s t e f f o r t h y p o thesis and b a s i c antim I. MAIN EFFECTS What i s r e f e r r e d to as the " c l a s s i c study" i n the review l i t e r a t u r e , was the f i r s t t o examine the p e r s u a s i v e outcome of an a c t u a l speech. F r a n k l y n Haiman's t h e s i s d i s e r t a t i o n i n 1948 examined the e f f e c t of source c r e d i b i l i t y on changing audience a t t i t u d e s v i a taped speeches (McCroskey & Young, 1981; McCroskey, 1972; Anderson and Clevenger; 1966; McGuire, 1969). The r e s u l t s of t h i s r e s e a r c h showed that the Surgeon General of the United S t a t e s was more e f f e c t i v e at changing audience a t t i t u d e s than the S e c r e t a r y f o r the Communist Party i n America or a Northwestern U n i v e r s i t y Sophomore, even though a l l three gave the same speech (McCroskey, 1972). There had been e a r l i e r s t u d i e s i n the 1930's, but these only l i n k e d a source with a p r o p o s i t i o n ; there was no a c t u a l speech (Anderson and Clevenger, 1963). From the Haiman study a number of s i m i l a r s t u d i e s f o l l o w e d , 3 0 but the next main input came from the work of C a r l Hovland and c o l l e a g u e s at Yale U n i v e r s i t y (Anderson and Clevenger, 1963). These r e s u l t s have been summarized i n t o the f o l l o w i n g c o n c l u s i o n s : 1) r e a c t i o n s to a communication are s i g n i f i c a n t l y a f f e c t e d by cues as to the communicator's expertness, t r u s t w o r t h i n e s s and i n t e n t i o n s ; 2) i d e n t i c a l p r e s e n t a t i o n s are judged more f a v o r a b l y when a t t r i b u t e d t o a h i g h c r e d i b i l i t y source; 3) i n two of the three s t u d i e s , immediate acceptance of the recommended o p i n i o n was g r e a t e r when a t t r i b u t e d to a high c r e d i b i l i t y source (Hovland et al.,1953). The authors note that even untrustworthy sources produced changes i n the favoured d i r e c t i o n , except that t h i s change was much l e s s than the h i g h c r e d i b i l i t y source and was due only t o arguments i n the message (Hovland et a l . , 1953). I t i s a l s o of i n t e r e s t to note that the Hovland s t u d i e s showed that the source c r e d i b i l i t y had no e f f e c t on l e a r n i n g of the content of the message (Hovland et a l . , 1953). Hovland et a l . (1953) p o i n t e d out that high source c r e d i b i l i t y was was e f f e c t i v e : a) f o r immediate o p i n i o n change; b) where a c l o s e a s s o c i a t i o n between source and r e c i p i e n t was made; 31 c) when a formal or i n f o r m a l commitment had been made. Otherwise, the e f f e c t of source i s di m i n i s h e d over time. In t h e i r 1963 review, Anderson and Clevenger s t a t e : "The f i n d i n g i s almost u n i v e r s a l that the ethos of the source i s r e l a t e d i n some way to the impact of the message" (p. 77, Anderson and Clevenger, 1963). In most cases a high c r e d i b i l t y source w i l l i n c r e a s e the acceptance of a message. However, there are some circumstances where t h i s i s not the case. In g e n e r a l , the main e f f e c t s of source c r e d i b i l i t y can be summarized by saying that high c r e d i b i l i t y sources are more p e r s u a s i v e than low c r e d i b i l i t y sources, with some e x c e p t i o n s . These ex c e p t i o n s are due to i n t e r a c t i o n e f f e c t s . I I . INTERACTION EFFECTS Other v a r i a b l e s , such as the c h a r a c t e r i s t i c s of the audience and of the message have been shown to modify the e f f e c t of the c r e d i b i l i t y of the source on the e f f e c t i v e n e s s of the message. 32 a. AUDIENCE VARIABLES i . P s y c h o l o g i c a l C h a r a c t e r i s t i c s E x t e n s i v e p s y c h o l o g i c a l t e s t i n g by P l a x and R o s e n f e l d (1980), l e a d t h e s e r e s e a r c h e r s t o c o n c l u d e t h a t h i g h c r e d i b i l i t y s o u r c e s l e a d t o h i g h a t t i t u d e change f o r poe p l e c h a r a c t e r i z e d as b e i n g : changeable and s o c i a l l y a s c e n d e n t , l i b e r a l i n d e c i s i o n making, c a p a b l e and r e s p o n s i b l e , i n t e l l i g e n t , f e l t inadequate and unworthy, had u n s t r u c t e r e d t h i n k i n g , s u b m i s s i v e and c o m p l i a n t b e f o r e a u t h o r i t y , changeable w i t h a tendancy t o i n t e r n a l c o n f l i c t s , and unsure i n new or u n f a m i l i a r s o c i a l s e t t i n g s . The r e v e r s e was t r u e f o r p e o p l e wth low a t t i t u d e change from the h i g h c r e d i b i l i t y s o u r c e . The low c r e d i b i l t y s ource l e a d t o h i g h a t t i t u d e change f o r people who were a s s u r e d of t h e i r r e a s o n i n g a b i l i t i e s , c o o p e r a t i v e and s t a b l e , had common sense and good judgement, were i n s i g h t f u l and v e r s a t i l e , c hangeable but c o n f i d e n t , l i t t l e e m o t i o n a l i n v o l v e m e n t w i t h s e n s i t i v e i s s u e s and were c a r e f u l and c a u t i o u s . Low a t t i t u d e change w i t h a low c r e d i b i l t y s o u r c e was c h a r a c t e r i z e d by pe o p l e who were c a p a b l e , but independent, committed t o s e n s i t i v e i s s u e s , c o n s e r v a t i v e and c o n v e n t i o n a l . The a u t h o r s s t a t e t h a t i t i s i n d i v i d u a l d i f f e r e n c e s t h a t o r d e r the response t o h i g h and low c r e d i b i l i t y messages ( P l a x and R o s e n f e l d , 1980). When the au d i e n c e i s h i g h l y a u t h o r i t a r i a n , i n v o l v e d or has a h i g h i n t e r n a l l o c u s of c o n t r o l , a h i g h c r e d i b l i t y s ource i s 33 e q u a l t o the e f f e c t i v e n e s s of a low c r e d i b i l i t y s ource ( D h o l a k i a and S t e r n t h a l , 1977). When the a u d i e n c e i s s e l f - a s s u r e d , c o n f i d e n t and o b j e c t i v e , a low c r e d i b i l i t y s ource can cause more s i g n i f i c a n t a t t i t u d e change than the h i g h c r e d i b i l i t y s ource ( P l a x and R o s e n f e l d , 1980) . Persons w i t h an e x t e r n a l l o c u s of c o n t r o l p e r c e i v e r e i n f o r c e m e n t s t o be beyond t h e i r c o n t r o l and a t t r i b u t a b l e t o chance, f a t e or p o w e r f u l o t h e r s . Hence a h i g h l y c r e d i b l e source i s more l i k e l y t o be a r e i n f o r c e m e n t than a low c r e d i b l i t y s o urce and t h e r e f o r e more p e r s u a s i v e . However, a per s o n s w i t h an i n t e r n a l l o c u s of c o n t r o l must j u s t i f y t h e i r b e h a v i o r themselves and so a r e not as i n f l u e n c e d by o t h e r s and source c r e d i b i l t y w i l l have no e f f e c t ( S t e r n t h a l e t a l . , 1978b). H i g h l y a u t h o r i t a r i a n p e o p l e a r e s t r o n g l y i n f l u e n c e d by the dominant cue i n a communication. T h e r e f o r e , where t h e r e a re no arguments t o s u p p o r t an advocacy, when arguments a r e b r i e f or when t h e message i s complex, t h e source becomes the dominant cue and s o u r c e c r e d i b i l i t y w i l l have an e f f e c t . Low a u t h o r i t a r i a n s , however, r e l y on m u l t i p l e cues and source c r e d i b i l i t y i s used o n l y when they have l i t t l e d e t a i l e d knowledge of the t o p i c , such as i n the case of a c u l t u r a l t r u i s m , b u t , not when they know something ( S t e r n t h a l e t a l . , 1978b). A n e u t r a l i n t i t i a l o p i n i o n made r e c e i v e r s more s u s c e p t i b l e t o s o u r c e c r e d i b i l i t y as opposed t o those who were p r o or con (Anderson and C l e v e n g e r , 1963). Audience v a r i a b l e s depend on message c o n t e n t f o r t h e i r 34 e f f e c t i v e n e s s . For example, a r e c e i v e r low i n s e l f esteem w i l l , i n comparison to a high s e l f esteem i n d i v i d u a l , y i e l d more to f o r c e f u l l y s t a t e d arguments. Whereas, the reverse might be true i n the case of arguments s t a t e d i n a q u a l i f i e d manner. For other arguments there may be l i t t l e or no d i f f e r e n c e between high or low s e l f esteem r e c e i v e r s ( F i s h b e i n & Azjen, 1981). In a d d i t i o n , t h e r e can be more than one i n t e r p r e t a t i o n of the e f f e c t s of an i n d i v i d u a l d i f f e r e n c e v a r i a b l e . For example,receivers high i n s e l f esteem should have more confi d e n c e i n the v a l i d i t y of t h e i r own b e l i e f s than low s e l f esteem r e c e i v e r s . Hence they would be expected to be l e s s swayed by arguments contained i n a message . Or, one c o u l d say high s e l f esteem i n d i v i d u a l s would f i n d i t e a s i e r to admit they were wrong and accept the communicator's p o s i t i o n than would i n d i v i d u a l s low i n s e l f esteem. - C o n f l i c t i n g h y p othesis c o u l d be d e r i v e d f o r such other audience v a r i a b l e s as i n t e l l i g e n c e , l o c u s of c o n t r o l , a u t h o r i t a r i a n i s m , r e l i g o s i t y or sex of the r e c e i v e r ( F i s h b e i n and Azjen, 1981). i i . Other Audience C h a r a c t e r i s t i c s In t h e i r summary of v a r i a b l e s , that might a f f e c t the i n f l u e n c e of source c r e d i b i l i t y , Anderson and Clevenger (1963) s t a t e d : 1) p e r s o n a l i t y was not r e l a t e d to s u s c e p t i b i l i t y to source c r e d i b i l i t y ; 2) i n t e l l i g e n c e and knowledge of the t o p i c were not r e l a t e d (three s t u d i e s ) , while one study showed the more i n t e l l i g e n c e 35 the l e s s s u s c e p t i b l e ; 3) sex was not r e l a t e d to s u s c e p t i b i l i t y to source c r e d i b i l i t y (three s t u d i e s ) , though one study showed females to be more s u s c e p t i b l e and another showed g i r l s to be more s u s c e p t i b l e ; 4) students were more s u s c e p t i b l e than a d u l t s ; When a person takes some b e h a v i o r a l a c t i o n i n response to an advocacy, t h i s behavior serves as the p e r s u a s i v e cue. (I signed the p e t i t i o n t h e r e f o r e I must have a f a v o r a b l e a t t i t u d e towards i t . ) In t h i s case, a low c r e d i b i l t i y source i s more p e r s u a s i v e , both f o r those who s i g n the p e t i t i o n and f o r those who do not. But, the person must be aware of the reasons f o r h i s behavior and the behavior request must be v o l u n t a r y ( S t e r n t h a l et a l . , 1987b). When invlolvement i n an i s s u e i s low, hig h c r e d i b i l i t y sources are more p e r s u a s i v e , i e . i n c r e a s i n g involvement reduced the e f f e c t of a h i g h l y c r e d i b l e source ( S t e r n t h a l et a l . , 1978b). The i n i t i a l o p i n i o n of the r e c i p i e n t can i n f l u e n c e the e f f e c t of source c r e d i b i l t y . When an audience i s f a v o r a b l y p r e d i sposed to an advocacy, a low c r e d i b i l i t y source induces g r e a t e r p e r s u a s i o n , while i f extremely n e g a t i v e l y predisposed, a high c r e d i b i l i t y source w i l l be more i n f l u e n t i a l . I n i t i a l o p i n i o n may be confounded with involvement as one study found people with extreme o p i n i o n s a l s o e x h i b i t e d g r e a t e r involvement 36 ( S t e r n t h a l et a l . , 1978b). S o u r c e / r e c i p i e n t s i m i l a r i t y can i n f l u e n c e source c r e d i b l i t y a c c o r d i n g to Hass (1981). A source w i l l have a g r e a t e r i n f l u e n c e i f he i s p e r e i v e d to be s i m i l a r to the r e c i p i e n t . T h i s s i m i l a r i t y b r i d g e s the gap between source c r e d i b i l i t y and source a t t r a c t i v e n e s s , making the source seem more c r e d i b i l e or more a t t r a c t i v e (Hass, 1981). I f s i m i l a r i t i e s are r e l e v a n t to the message t o p i c , p e r s u a s i o n i s i n c r e a s e d due to an i n f l u e n c e on c r e d i b i l i t y . The a t t i t u d e of the r e c e i v e r , compared to that of the message source can i n f l u e n c e b e l i e f i n a message. Hass (1981) summarized the r e s e a r c h on s o u r c e / r e c i p i e n t descrepancy. S t u d i e s show that where the a u d i e n c e - r e c e i v e r a t t i t u d e i s i n o p p o s i t i o n to the p o s i t i o n recommended i n the message, a) a hi g h c r e d i b i l i t y source i s more e f f e c t i v e than a low c r e d i b i l i t y source; b) the more a t t i t u d e change advocated by the source, the more change evoked, up to a drop o f f p o i n t ; and c) t h i s drop o f f p o i n t occurs at a more extreme s o u r c e / r e c i p i e n t d i s c r e p e n c y f o r a high c r e d i b i l i t y source than f o r a low c r e d i b i l i t y source (Hass, 1981). When the message i s incongruent with the source's best i n t e r e s t , or where a source j u s t i f i e s h i s p o s i t i o n with arguments that are u n f a m i l i a r to the message r e c i p i e n t , a low c r e d i b i l i t y source i s as e f f e c t i v e as a high c r e d i b i l i t y source (Hass, 1981). 37 b. MESSAGE VARIABLES Va r i o u s aspects of the message i t s e l f a c t both i n t h e i r own r i g h t and along with audience and source v a r i a b l e s to i n f l u e n c e the e f f e c t i v e n e s s of the message. The use of arguments and evidence, as w e l l as s t y l e are c h a r a c t e r i s t i c s of the message i t s e l f which can, on t h e i r own, act to i n f l u e n c e the e f f e c t i v e n e s s of the message. The descrepancy of the arguments in the message to the r e c e i v e r ' s p o i n t of view i n f l u e n c e the acceptance of the message. The i n c o n g r u i t y of the arguments presented i n the message with the source's best i n t e r e s t s w i l l a l s o i n f l u e n c e the acceptance of the message, i i i . Arguments i n the message Message v a r i a b l e s d i s t i n g u i s h the l i m i t i n g c o n d i t i o n s under which the hi g h c r e d i b i l i t y source causes more o p i n i o n change than the low c r e d i b i l i t y source: 1) when the message does not stand on i t s own, i e , poor arguments and a s s e r t i o n s ; 2) when the high c r e d i b i l i t y source g i v e s a message that would otherwise be s t r o n g l y r e j e c t e d on i t s own m e r i t , due to a tendancy to d i s s o c i a t e the source and the message content (Hovland et a l . , 1953). If a message i s s t r u c t u r e d to disarm a r e c i p i e n t ' s counterarguments e a r l y i n the message and av o i d s suggesting new counterarguments, the message i s l i k e y to be more p e r s u a s i v e when the high c r e d i b i l t y source i s used (Hass, 1981) . 38 There has been much debate r e g a r d i n g the e f f e c t of p r e s e n t i n g j u s t one s i d e of the argument versus both s i d e s . In 1963, a review p u b l i s h e d mixed r e s u l t s : 1. a 1-sided message was more e f f e c t i v e i f the audience favoured the advocated view, and had no high school education; 2. a 2-sided message was more e f f e c t i v e i f the evidence used supported one s i d e only, f o r audience with high s c h o o l e d u c a t i o n ; 3. a 2-sided message produced no s i g n i f i c a n t d i f f e r e n c e i n a t t i t u d e change than a 1-s i d e d message (Anderson and Clevenger, 1963). Two-sided appeals are p a r t i a l l y congruous, as arguments both favourable and unfavourable to the speaker are presented. In t h i s s i t u a t i o n , two-sided appeals i n themselves are more pe r s u a s i v e than one-sided, p r o v i d e d the unfavourable s i d e i s presented f i r s t , i s r e f u t e d i n a compelling manner and c i t e s only unfavourable arguments a l r e a d y known to the audience. Rephrasing t h i s , the high c r e d i b i l i t y source w i l l enhance the source's i n f l u e n c e when the i n f o r m a t i o n presented i n the message i s c o m p e l l i n g , congruous wth the source's best i n t e r e s t and when the source i s c h a r a c t e r i z e d as a person who has maintained h i s or her p o s i t i o n over time. There i s no systematic c r e d i b i l t y e f f e c t expected , however, when the 3 9 communicator i s p a r t i a l l y congruous or i s a c o n v e r t . A low c r e d i b i l i t y source can i n c r e a s e h i s persuasiveness by assuming an incongruous p o s i t i o n . I t i s b e t t e r to ignore o p p o s i t i o n arguments i f the audience i s f a v o u r a b l e to the advocacy and of low i n t e l l i g e n c e . However, one should r e f u t e oppostion arguments i f the audience i s unfavourable and of high i n t e l l i g e n c e (McGuire, 1969). There are ambiguous r e s u l t s r e g a r d i n g : 1. whether the stongest arguments should go at the beginning or end of the message; 2. whether o p p o s i t i o n arguments should be r e f u t e d before or a f t e r support arguments. (McGuire, 1969) i v . Message S t y l e The message s t y l e r e f e r s to language, tone and sentiment expressed. There are ambiguous r e s u l t s r e garding the use of humour and and whether the appeal should be emotional or r a t i o n a l (McGuire, 1969). Other f a c t o r s i n v e s t i g a t e d at that time found that the use of a u t h o r i t y i n quotes d i d not i n c r e a s e p e r s u a s i o n . (Anderson and Clevenger, 1963). Reinforcements w i t h i n the message, such as p r a i s e f o r a c c e p t i n g the advocated a t t i t u d e and/or support arguments fo r the advocacy i n c r e a s e the amount of a t t i t u d e change (McGuire, 1969). Regarding message s t y l e , the use of metaphor was found to 4 0 be e f f e c t i v e at i n c r e a s i n g the amount of a t t i t u d e change, due to i t s e f f e c t on e v a l u a t i o n of the source who i s then seen as more i n t e l l i g e n t or as e n t e r t a i n i n g and p l e a s i n g (McGuire, 1969). I t i s b e t t e r to i n c l u d e the c o n c l u s i o n i n the message , as t h i s ensures t h a t the r e c e i v e r gets the p o i n t , i t makes the source seem more sure of h i m s e l f and i f i t i s a d e s i r e a b l e c o n c l u s i o n , i t can i n c r e a s e the m o t i v a t i o n of the r e c e i v e r to agreee. T h i s does however, i n t e r a c t with i n d i v i d u a l d i f f e r e n c e s (McGuire, 1969). There i s some ambiguity as to the whether the c o n c l u s i o n , i f i n c l u d e d should be p l a c e d f i r s t or l a s t . I f f i r s t , i t may a l i e n a t e those r e c e i v e r s who were opposed to the advocacy and i t may show the source to be b i a s e d , with i n t e n t i o n to persuade. But, the advantages of p l a c i n g the c o n c l u s i o n f i r s t i n c l u d e an i n c r e a s e i n comprehension, a focus of a t t e n t i o n , and d e f i n i n g of a c l e a r p o s i t i o n and focus of the message. The l a t t e r leads to a f e e l i n g of c l o s u r e s a t i s f a c t i o n and l e s s a n x i e t y r e g a r d i n g a missed p o i n t . There i s i n t e r a c t i o n with message complexity , i n t e l l i g e n c e and i s s u e f a m i l i a r i t y (McGuire, 1969). Agreeable i n f o r m a t i o n should be p l a c e d f i r s t and then the d i s a g r e e a b l e , f o r optimum a t t i t u d e change (McGuire, 1969). v. Use of Evidence i n the Message I n v e s t i g a t i o n s were a l s o made i n t o the amount of evidence and documentation used i n the message (Anderson and Clevenger,1963). I f the argument was supported, but without documentation or i f i t was supported with documents and the source was c a l l e d an expert, a g r e a t e r s h i f t i n o p i n i o n r e s u l t e d 41 than with a non-expert source. When j u s t the support and documentation were made, the e f f e c t was no g r e a t e r than with a g e n e r a l i z a t i o n , that i s , no evidence or documentation (Anderson and Clevenger, 1963). Use of su p p o r t i v e f a c t u a l i n f o r m a t i o n from a source other than the speaker inceased the persuasiveness of a low c r e d i b i l i t y source o n l y , p r o v i d e d the evidence was u n f a m i l i a r to the audience. No c r e d i b i l i t y main e f f e c t was found when u n f a m i l i a r evidence was used as i n an a t t a c k on a c u l t u r a l t r u i s m , an is s u e that most people have accepted as being t r u e , but, f o r which they have l i t t l e s u p p o r t i n g evidence. A low c r e d i b i l t y source can i n c r e a s e t h e i r p e r s uasiveness by using evidence to support t h e i r p o s i t i o n ( S t e r n t h a l et a l . , 1978b). The message w i l l be r e l a t i v e l y i n e f f e c t i v e i f the evidence used i s u n r e l a t e d to the arguments, and the arguments are u n r e l a t e d to the primary b e l i e f s u n d e r l y i n g the dependant v a r i a b l e . S t e r n t h a l , P h i l l i p s and Dho l a k i a , i n t h e i r 1978 review of message f a c t o r s suggest the f o l l o w i n g are of importance: 1) Discrepancy 2) Threat 3) Message I n c o n g r u i t y 4) Use of Evidence 42 v i . Discrepancy Discrepancy r e f e r s to the d i f f e r e n c e between the r e c e i v e r ' s p o i n t of view and the p o i n t of view expressed by the source i n the message. A h i g h l y c r e d i b i l e source i s more i n f l u e n t i a l than a low c r e d i b l i t y source when the message dis c r e p a n c y i s r e l a t i v e l y h igh, but not extreme. There i s l e s s or no c r e d i b i l i t y e f f e c t when the message di s c r e p a n c y i s r e l a t i v e l y low. S e l e c t i v e exposure t h e o r i e s d e s c r i b e the tendancy f o r a person to a) seek out i n f o r m a t i o n that confirms h i s preconceptions and b) a c t i v e l y a v o i d i n f o r m a t i o n that d i s c o n f i r m s them. The l a t t e r p o i n t , b ) , has l i t t l e support i n the r e s e a r c h , and, r e s u l t s f o r the former are a l s o ambiguous (McGuire, 1969). I f the message i s d i s c r e p a n t , there i s a tendancy f o r the r e c e i v e r to d i s t o r t the i n f o r m a t i o n as being l e s s f a i r , l e s s l o g i c a l , l e s s i n t e r e s t i n g , e t c . and a l s o to d i s t o r t the r e l a t i v e p o s i t i o n of the advocacy on an a t t i t u d e continuum. Research showed that i f a message i s only s l i g h t l y d i s c r e p a n t , from the r e c e i v e r ' s p o s i t i o n , the r e c e i v e r d i s t o r t s i t as being c l o s e r to t h e i r own p o s i t i o n than i t r e a l l y i s . T h i s i s c a l l e d " a s s i m i l a t i o n e r r o r " . "Contrast e r r o r " occurs when the message i s very d i s c r e p a n t and the r e c e i v e r d i s t o r t s i t as being even f u r t h e r away from t h e i r p o s i t i o n than i t r e a l l y i s (McGuire, 1969). The g r e a t e r amount of change urged i n a message, the g r e a t e r the obtained a t t i t u d e change, up to a f a l l i n g - o f f p o i n t . 43 A high c r e d i b i l i t y source w i l l endure a g r e a t e r d i s c r e p a n c y before the f a l l i n g o f f p o i n t . than a low c r e d i b l i t y source (McGuire, 1969). The more i n v o l v e d a person i s , i e committed to the c o r r e c t n e s s of t h e i r i n i t i a l o p i n i o n , the s m a l l e r the impact of a h i g h l y descrepent message (McGuire, 1969). I f a person has a n e u t r a l o p i n i o n , the high c r e d i b i l t i y source causes the most o p i n i o n change when a t t r i b u t e d to an o p i n i o n a t e d message and a low c r e d i b i l i t y source i s more e f f e c t i v e with a non-opinionated message. I f the person has a negative o p i n i o n to s t a r t , i n c r e a s i n g the opinionatedness of the message decreases the persuasion f o r both the hi g h and low c r e d i b i l i t y sources. Source, mes.sage and audience f a c t o r s may serve t o f a c i l i t a t e , or i n h i b i t acceptance of arguments contained i n a message, and, they have a cumulative e f f e c t on the o v e r a l l e f f e c t i v e n e s s of the message. Acceptance of a given argument i n c r e a s e s with o v e r a l l f a c i l i t a i o n and decreases with the disc r e p a n c y between the b e l i e f of the source and that of the r e c e i v e r ( F i s h b e i n & Azjen, 1981) . Th i s i m p l i e s that f a c i l i t a t i n g f a c t o r s such as source c r e d i b i l t i y and r e c e i v e r s e l f - e s t e e m w i l l i n f l u e n c e the acceptance of an argument p r i m a r i l y at hi g h l e v e l s of d i s c r e p a n c y . A l s o , a d d i t i o n a l f a c i l i t a t i n g f a c t o r s may do l i t t l e to i n c r e a s e the acceptance of an argument i f the o v e r a l l f a c i l i t a t i o n i n a message i s high to s t a r t with. 44 v i i . Threat When p h y s i c a l or s o c i a l consequences of non-compliance are i n c l u d e d i n a message, the g r e a t e s t a t t i t u d e s h i f t was found when a hig h c r e d i b i l i t y source presented a s t r o n g l y t h r e a t e n i n g message. In a d d i t i o n , i n the s o c i a l t h r e a t s i t u a t i o n , a high c r e d i b i l t i y source i s more e f f e c t i v e , whether the message i s op i n i o n a t e d or not. When f e a r appeals are used, there i s a p o s i t i v e r e l a t i o n s h i p between the i n t e n s i t y of the fe a r appeal and the amount of a t t i t u d e change. T h i s i s not a simple r e l a t i o n s h i p though, and depends on the r e c e i v e r ' s l e v e l of a n x i e t y and the s p e c i f i c i t y and e f f i c a c y of the urged s o l u t i o n . (McGuire, 1969). v i i i . I n c o n g r u i t y of Message If the message i s incongruent with the source's best i n t e r e s t s , or i f the source j u s t i f i e s h i s p o s i t i o n with arguments that are u n f a m i l i a r to the message r e c i p i e n t s , a high c r e d i b i l t y source w i l l be equal to a low c r e d i b i l t y source i n the amount of a t t i t u d e change evoked ( S t e r n t h a l and Dho l a k i a , 1977). When i n f o r m a t i o n that i s incongruous with the source's best i n t e r e s t s i s presented, a hig h c r e d i b i l i t y source i s as i n f l u e n t i a l as a low c r e d i b i l i t y source. But, a high c r e d i b i l i t y source was more p e r s u a s i v e than a low c r e d i b i l i t y source when the source made arguments that were congruent t o t h e i r own s e l f - i n t e r e s t s . A source c u r r e n t l y s u p p o r t i n g a 45 p o s i t i o n t h at i s incongruent with t h e i r p a s t , i e a convert, induces g r e a t e r i n f l u e n c e f o r t h e i r advocacy that the source who has always supported that p o s i t i o n . Research suggests that we tend to f e e l communicators who express views s i m i l a r to our own are more c r e d i b l e than those who express c o n t r a r y views (McCroskey, 1972) . S i m i l a r i t i e s i n background, experience and a t t i t u d e s w i l l h e l p to i n c r e a s e the d e r i v e d ethos i f the audience i s f a v o u r a b l y disposed to these a t t r i b u t e s . One study reviewed by McCroskey, (1972) suggests that such s i m i l a r i t i e s do not have to be r e a l to have an e f f e c t . Even i f the source's advocacy does not t u r n out to be as i n i t i a l l y s t a t e d , he w i l l s t i l l have g r e a t e r success at modifying a t t i t u d e s than a source who makes no attempt to e s t a b l i s h common ground. If the message i s incongruous- with the source's best i n t e r e s t , or the source j u s t i f i e s h i s p o s i t i o n with arguments that are u n f a m i l i a r to the message r e c i p i e n t s , a high c r e d b i l i t y source i s equal to a low c r e d i b i l i t y source i n the amount of a t t i t u d e change evoked (Dholakia and S t e r n t h a l , 1977). C o n f l i c t i n g f i n d i n g s i n the l i t e r a t u r e r e garding the optimum format of the message may be due to d i f f e r e n c e s i n d i s c r e p a n c y l e v e l s used i n the study, the inherent presence of other f a c i l i t a t i n g f a c t o r s , or ignorance of message content such as f a c t u a l evidence, relevance of evidence to the major arguments and the r e l a t i o n of these arguments to the dependent t a r g e t v a r i a b l e ( i e b e l i e f i n the message). According to F i s h b e i n and Ajzen (1981), of the s t u d i e s comparing v a r i o u s 46 types of p e r s u a s i v e appeals , (such as r a t i o n a l vs. emotional; high f e a r vs. low f e a r ; 1-sided v s . 2-sided; c o n c l u s i o n vs. no c o n c l u s i o n ; and order of arguments ) none "...have been found to have c o n s i s t e n t and r e p l i c a b l e e f f e c t s on the persuasiveness of the message" (p358). In the s t u d i e s , a l l message manipulations v a r i e d both i n the kind and amount of i n f o r m a t i o n i n c l u d e d , except f o r those s t u d i e s on order of p r e s e n t a t i o n . V a r i a t i o n i n the type of appeal were confounded with d i f f e r e n c e s i n the content of the message. E f f e c t i v e n e s s of type of appeal t h e r e f o r e depends p r i m a r i l y on the content of the message employed i n the study ( F i s h b e i n and Ajzen, 1981). The e f f e c t s of source c r e d i b i l i t y on amount of change w i l l a l s o depend on the content of the message used. V a r i a t i o n s i n the source c r e d i b i l i t y had a s i g n i f i c a n t e f f e c t on a t t i t u d e change on l y when minimal evidence was pr o v i d e d . When the message c o n t a i n e d strong s u p p o r t i v e evidence, there was no source e f f e c t . R e c e i v e r s change t h e i r primary b e l i e f s on the b a s i s of the s u p p o r t i v e evidence, i r r e s p e c t i v e of the source's c r e d i b i l i t y . Research on a t t r a c t i v e n e s s and power has produced even l e s s c o n s i s t e n t f i n d i n g s than r e s e a r c h on source c r e d i b i l i t y , again due to message content ( F i s h b e i n and Azjen, 1981). When st u d y i n g the di s c r e p a n c y dimension, i t i s important to make the message as extreme as p o s s i b l e to ensure that the dis c r e p a n c y dimension w i l l capture the most extreme p o s i t i o n s (Bochner and Insko, 1976) Accord i n g t o F i s h b e i n and Azjen (1981), the primary purpose 47 of the message content should be to change primary b e l i e f s about the e x p e c t a t i o n s of s p e c i f i c r e f e r e n t s . Only i n t h i s manner can the s u b j e c t i v e norm be a f f e c t e d . The b a s i c s t r u c t u r e of a message are i t s arguments, and the evidence used to support the arguments. I t i s assumed, though r a r e l y t e s t e d , that acceptance of the s u p p o r t i v e evidence w i l l r e s u l t i n acceptance of the argument and, that acceptance of the argument w i l l l e a d to a change i n the c o n l u s i o n . The argument alone can change b e l i e f i f i t i s novel and p r e v i o u s l y n o n - s a l i e n t . But, acceptance of an argument does not n e c e s s a r i l y l e a d to y e i l d i n g or change i n corresponding b e l i e f , unless i t i n f l u e n c e s a s u f f i c i e n t number of primary b e l i e f s . There are many steps i n t h i s process and the message should c o n s i d e r them a l l ( F i s h b e i n and Azjen, 1981). I l l . THEORIES TO EXPLAIN THE SOURCE EFFECT Numerous i n v e s t i g a t o r s have researched the f a c t o r s that i n f l u e n c e the e f f e c t i v e n e s s of a p e r s u a s i v e communication, one of these f a c t o r s being source c r e d i b i l i t y . The main t h e o r i e s that have emergerd from t h i s r e s e a r c h a r e : 1) C o g n i t i v e Response Theory A counterarguing theory by the Hovland group at Yale (Hovland, J a n i s and K e l l e y , 1953). 2) Congruity Theory -A balance theory (Osgood and Tannenbaum,1957). 3) C o g n i t i v e Dissonance Theory -J u s t i f y i n g of c h o i c e s ( F e s t i n g e r , 1957). 4) S e l f - P e r c e p t i o n Theory -48 Reasons f o r behavior ( i n S t e r n t h a l and Dho l a k i a , 1977) 5) A t t r i b u t i o n Theory -Reasons f o r behavior ( S t e r n t h a l et a l . , 1978b) 6) Least E f f o r t Hypothesis -Behavior causing minimum r e s i s t a n c e (Hass, 1981) I. COGNITIVE RESPONSE THEORY Although i t was once assumed that acceptance of a communication was a f u n c t i o n of l e a r n i n g or the r e t e n t i o n of the content, there i s l i t t l e e m p i r i c a l evidence to support t h i s (Greenwald, 1968). Instead, support has been found f o r the hypothesis that a r e c e i v e r rehearses a t i t u d e - r e l e v a n t thoughts that are aroused by the message content, r a t h e r than r e h e a r s i n g the a c t u a l content i t s e l f (Greenwald, 1968). These a t t i t u d e r e l e v a n t thoughts , which c o n s t i t u t e the c o g n i t i v e response content, are generated by the r e c e i v e r when making a d e c i s i o n to accept or r e j e c t new i n f o r m a t i o n . T h i s i n v o l v e s r e l a t i n g the new i n f o r m a t i o n to the e x i s t i n g a t t i t u d e s , knowledge and f e e l i n g s . P ersuasion takes p l a c e when the r e c e i v e r rehearses a t t i t u d e thoughts ( c o g n i t i v e response content) that support the advocated p o s i t i o n , while no pe r s u a s i o n occurs when content opposing the advocacy i s rehearsed. . The components that i n f l u e n c e the " c o g n i t i v e response content" i n c l u d e s e t t i n g , source, communication content and r e c e i v e r c h a r a c t e r i s t i c s (Greenwald, 1968). C o g n i t i v e response r e f e r s to the response of an i n d i v i d u a l to a p e r s u a s i v e appeal where the i n d i v i d u a l rehearses t h e i r 49 i s s u e - r e l e v a n t thoughts and those presented to them in the message. Message r e j e c t i o n occurs when the r e c e i v e r i s opposed to the communicator's advocacy and generates counterarguments to the a s s e r t i o n made in the message. Source c r e d i b i l i t y a c t s a l s o as a mediating f o r c e on these counterarguments, i n that a high c r e d i b i l i t y source i n h i b i t s c o u n t e r a r g u i n g , while a low c r e d b i l i t y source does not. Thus, a h i g h c r e d i b i l i t y source i s more p e r s u a s i v e ( S t e r n t h a l et a l . , 1978a, c i t i n g Greenwald, 1968). However, S t e r n t h a l et a l . (1978a) p o i n t out that t h i s i s true only i f the r e c i p i e n t has a n e g a t i v e p r e d i s p o s i t i o n toward the advocacy. If the r e c i p i e n t has a p o s i t i v e p r e d i s p o s i t i o n toward the advocacy, there i s a g r e a t e r need to i n s u r e that a p o s i t i o n they agree with i s being adequately represented. Thus, when the source i s low i n c r e d i b i l i t y , there i s more genera t i o n of support arguments and a low c r e d i b i l i t y source i s more pe r s u a s i v e ( S t e r n t h a l et a l . , 1978a). However t h i s may not be too s i g n i f i c a n t s i n c e the r e c e i v e r i s a l r e a d y f a v o u r a b l e toward the advovacy. Thus the h y p o t h e s i s evolved that the i n i t i a l o p i n i o n of the r e c i p i e n t i s important. I f the i n i t i a l o p i n i o n i s negative toward the adovocacy, a high c r e d i b i l i t y source i s more l i k e l y to be p e r s u a s i v e . I f p o s i t i v e , a low c r e d i b i l i t y source, and i f n e u t r a l , there i s no systematic p e r s u a s i v e e f f e c t as counter arguments equal support arguments. S t e r n t h a l et a l . (1978a) i n t h e i r study found that when the message r e c i p i e n t s were f a v o u r a b l y predisposed to the 50 message advocacy, the l e s s c r e d i b l e source induced more agreement and support arguments than the high c r e d i b l i t y source, as p r e d i c t e d . And, i f n e g a t i v e l y p r e d i s p o s e d , the high c r e d i b l i t y source caused g r e a t e r agreement with the advocacy, but there was no source e f f e c t on the ge n e r a t i o n of support arguments, though t h i s may have been due to u n f a m i l i a r i t y with the i s s u e Counterargumentation i s only a s p e c i a l case of the c o g n i t i v e response f o r m u l a t i o n . C o g n i t i v e response a n a l y s i s accounts f o r a wider v a r i e t y of the observed e f f e c t s and i t addresses s i t u a t i o n s where i n d i v i d u a l s are both f a v o u r a b l y and unfavourably p redisposed to a communication. The l i m i t a t i o n s of counter a r g u i n g i s that i t a p p l i e s only to those s i t u a t i o n s where i n d i v i d u a l s have an unfavourable d i s p o s i t o n toward an advocacy ( S t e r n t h a l et a l . , 1978b). C o g n i t i v e response a n a l y s i s e x p l a i n s that a response to an appeal e n t a i l s g eneration and r e h e a r s a l of one's own a t t i t u d e -r e l e v a n t thoughts and those i n c l u d e d i n the message. I t i n v o l v e s the short-term memory, where i n f o r m a t i o n being a c t i v e l y processed i s h e l d and i t a l s o i n v o l v e s the lo n g - term memory where i n f o r m a t i o n processed e a r l i e r i s s t o r e d . The incoming message e n t e r s the short-term memory as thoughts or c o g n i t i v e responses. These thoughts t r i g g e r the r e t r i e v a l of f u r t h e r i s s u e - r e l a t e d i n f o r m a t i o n , or i n i t i a l o p i n i o n s from long-term storage which are then r e g i s t e r e d in the short-term memory. Thoughts i n the short-term memory are rehearsed and c o n s o l i d a t e d and e v e n t u a l l y determine the response 51 to an appeal. T h i s theory s t r e s s e s the importance of i n i t i a l o p i n i o n as a determinant of i n f l u e n c e or p e r s u a s i o n . If a r e c i p i e n t i s opposed to the message content, incoming i n f o r m a t i o n causes r e t r i e v a l of negative thoughts or counterarguments from the long-term memory. These enter the short-term memory where they are rehearsed and t h e r e f o r e l i k e l y to cause r e j e c t i o n of the message. Conversely, i f one i s favo u r a b l e toward the message content, support arguments are r e t r i e v e d from the long-term memory rehearsed and are l i k e l y to cause acceptance of the message con t e n t . S t e r n t h a l et a l . (1978b) were able to show that t h i s theory accounts f o r the e f f e c t s of source c r e d i b l i t y on a t t i t u d e change. I f i n i t i t a l l y opposed to the message content, a high c r e d i b i l i t y source w i l l i n h i b i t the genera t i o n and r e t r e i v a l of counterarguments from the long-term memory, while a low c r e d i b i l i t y source w i l l not. I f i n i t i a l l y f a v o u r a b l e to the message, more support arguments are generated i f i t i s only a moderately c r e d i b l e source as the r e c e i v e r i s motivated to generate support f o r the p o s i t i o n . I f a high c r e d i b i l i t y source says so, there i s no need f o r support arguments ( S t e r n t h a l et al.,1978b). Message and source c r e d i b i l i t y i n t e r a c t i o n s are e x p l a i n e d by t h i s theory. A h i g h l y d i s c r e p a n t or t h r e a t e n i n g message evokes counterargumenation that i s o f f - s e t by a h i g h l y c r e d i b l e source, but not by a low c r e d i b i l i t y source. When there i s low di s c r e p a n c y or t h r e a t , there i s l i t t l e counterargumentation and 52 c r e d i b i l i t y does not a f f e c t the outcome ( S t e r n t h a l et a l . , 1978b). If the evidence i s u n f a m i l i a r or the message i s incongruent with the source's best i n t e r e s t s , c o u n t e r a r g u i n g i s again i n h i b i t e d and no c r e d i b i l i t y e f f e c t i s observed ( S t e r n t h a l et a l . , 1978b) Audience v a r i a b l e s and source c r e d i b l i t y i n t e r a c t i o n s are a l s o e x p l a i n e d by c o g n i t i v e response theory. Persons with high involvement and h i g h i n t e r n a l l o c u s of c o n t r o l f a c i l i t a t e counterarguments themselves and source c r e d i b i l i t y has no systematic e f f e c t . With low involvement or i n t e r n a l l o c u s of c o n t r o l , counterarguments are reduced and c r e d i b i l t y does a f f e c t the argumentaton pr o c e s s . In t h i s case, a high c r e d i b i l i t y source i s more p e r s u a s i v e . Since high a u t h o r i t a r i a n s r e l y on the dominant p e r s u a s i v e cue, a h i g h l y c r e d i b i l e source w i l l be more p e r s u a s i v e than a low c r e d i b i l i t y source when the message c o n t a i n s no support arguments and i s h i g h l y complex. If the message has support arguments and i s not too complex, the message serves as the dominant cue and the source makes no d i f f e r e n c e ( S t e r n t h a l et a l . , 1978b). Low a u t h o r i t a r i a n s use m u l t i p l e cues f o r a t t i t u d e judgements. When a r e c i p i e n t has no b a s i s f o r judging the message content, such as when a c u l t u r a l t r u i s m i s opposed, the source w i l l serve as the dominant cue and the source w i l l a f f e c t p e r s u a s i o n ( S t e r n t h a l et a l . , 1978b). In summary, i f only source cues are present, a high c r e d i b i l i t y source i s more per s a u a s i v e than a low c r e d i b i l i t y 53 source f o r those opposed t o the advocacy and a low c r e d i b i l i t y s o urce i s more p e r s u a s i v e f o r t h o s e f a v o u r a b l e t o the advocacy ( S t e r n t h a l e t a l . r 1978b). When the i n t e r a c t i o n e f f e c t s of message and i n d i v i d u a l a u d i e n c e v a r i a b l e s a r e p r e s e n t , source c r e d i b i l i t y has an o b s e r v a b l e e f f e c t when these v a r i a b l e s induce moderate l e v e l s of c o u n t e r a r g u m e n t a t i o n . T h i s would occur when t h e r e was s u b s t a n t i a l t h r e a t or d i s c r e p a n c y , i n which case a h i g h c r e d i b i l i t y s o u r c e would s e r v e t o i n h i b i t t he counterarguments and i n c r e a s e p e r s u a s i o n . When t h e r e i s no ev i d e n c e or the message i s not incon g r u o u s w i t h the s o u r c e ' s b e s t i n t e r e s t s , t h e r e i s no i n h i b i t i o n of c o u n t e r a r g u m e n t a t i o n , or when i n d i v i d u a l d i f f e r e n c e s cause c o u n t e r a r g u m e n t a i o n , ( i n v o l v e m e n t , i n t e r n a l l o c u s of c o n t r o l ) c r e d i b i l i t y of sour c e has no e f f e c t . A l t h o u g h we speak of source e f f e c t s , i t i s a c t u a l l y changes i n an i n d i v i d u a l r e c i p i e n t (which depend on b e l i e f about the sour c e ) t h a t r e s u l t i n d i f f e r e n c e s i n p e r s u a s i o n . By a l t e r i n g the b e l i e f about the s o u r c e , t h e same message w i l l be p r o c e s s e d d i f f e r e n t l y , t h e r e b y a l t e r i n g i t s p e r s u a s i v e e f f e c t . In h i s r e v i e w , Hass ( 1 9 8 1 ) , s t a t e s t h a t Hovland and h i s c o l l e a g u e s i n i t i a l l y b e l i e v e d t h a t the sour c e i n f l u e n c e d the l e a r n i n g of the message c o n t e n t and i f t h e arguments were l e a r n e d , p e r s u a s i o n o c c u r r e d . However, t h i s i s not s u p p o r t e d by r e s e a c h e v i d e n c e t h a t d i f f e r e n c e s i n source p e r s u a s i v e n e s s a r e accompanied by d i f f e r e n c e s i n comprehension (Hovland e t a l . , 1953; M c G u i r e , 1969). People seem t o l e a r n the message c o n t e n t 54 and then decide to agree or d i s a g r e e wth i t . Instead, source c h a r a c t e r i s t i c s make the arguments seem st r o n g e r or weaker, depending on who i s b e l i e v e d to have presented them. C o g n i t i v e response theory suggests that the more ab l e a r e c i p i e n t i s to generate counterarguments to the p o i n t s r a i s e d i n the message, the l e s s he or she w i l l be persuaded (Hass, 1981). Counterarguments, serve, v i a the summoning f o r t h of i n f o r m a t i o n a l r e a d y posessed, t o : a) Defend ones own p o s i t i o n - the p e r s u a s i v e attempt i s r e s i s t e d by j u s t i f y i n g r e j e c t i o n of arguments s u p p o r t i n g a c b n t e r a t t i t u d i n a l p o s i t i o n ; b) Compare new i n f o r m a t i o n to o l d - to determine i f the new i n f o r m a t i o n " f i t s " i n t o e x i s t i n g knowledge and to determine the worth or s u b j e c t i v e c o r r e c t n e s s of the new i n f o r m a t i o n (Hass, 1981) . I t i s u s e f u l to be open to new i n f o r m a t i o n that improves our view of p h y s i c a l and s o c i a l r e a l i t i e s . On the other hand, p e r s i s t a n t a t t i t u d e s f a c i l i t a t e behaviour and promote the s t a b i l i t y necessary f o r optimal s o c i a l i n t e r a c t i o n . These two r e a c t i o n s are r e l a t e d t o commitment: when a person i s minimally committed to a p o s i t i o n , openness, f l e x i b i l i t y , and r e d e f i n i t i o n dominate. But, when a person i s s t r o n g l y committed, clo s e d n e s s , s t a b i l i t y and s e l f p r o t e c t i o n p r e v a i l . Thus, when a person i s uncommitted, or open, he may be more i n t e r e s t e d i n examining the p e r s u a s i v e content to determine the 55 best p o s i t i o n to take. The message i s examined f o r l o g i c a l flaws and c o n t r a d i c t i o n s i n content and o b j e c t i v e arguing i n order to e s t a b l i s h the v e r a c i t y of the message content. Conversely, i f a person i s committed to a p o s i t i o n through p r e v i o u s d e c i s i o n s and a c t i o n s , a person i s l e s s t o l e r a n t of opposing views and i s d e f e n s i v e towards a committed stand. The purpose of c o u n t e r a r g u i n g i n t h i s case i s to r e s i s t p ersuasion by s u p p o r t i n g one's own p o s i t i o n and r e f u t i n g that of the source as w e l l as examining the message content. T h e r e f o r e , i n terms of source c r e d i b i l i t y , i f a person i s uncommitted, the content of the message i s examined to determine v a l i d i t y . I f the accuracy of the i n f o r m a t i o n i f suspect, f o r example, i f given by a low c r e d i b l i t y source, there w i l l ensue a more s t r i n g e n t examination of the new i n f o r m a t i o n and l e s s p e r s u a s i o n w i l l r e s u l t . But, with a high c r e d i b i l i t y source, i n f o r m a t i o n i s l e s s suspect and so there are l e s s counterarguments generated and more persuasion i s the outcome. If a person i s committed, they are d i s i n c l i n e d t o y i e l d to the persuasion and to produce counterarguments to r e s i s t change that might r e s u l t i n a negative outcome. The negative r e s u l t s t h a t might ensue i f a person changes h i s or her o p i n i o n p o s s i b l y i n c l u d e : 1) l e s s e n i n g of esteem from o t h e r s ; 2) admission of p r e v i o u s e r r o r ; 3 ) r e d u c t i o n of c r e d i b i l i t y as a source of i n f o r m a t i o n ; 4) blame f o r m i s l e a d i n g o t h e r s ; 56 5) c o n f l i c t i n choosing a course of a c t i o n . If a h i g h l y c r e d i b l e source i s p e r c e i v e d to be able to present a stronger a t t a c k on a committed r e c i p i e n t ' s o p i n i o n , more co u n t e r a r g u i n g w i l l o c c u r r and l e s s p e r s u asion w i l l r e s u l t . T h i s i s j u s t the opposite f o r an uncommitted i n d i v i d u a l who w i l l counterargue more with a l e s s c r e d i b l e source. T h i s has been confirmed by v a r i o u s r e s e a r c h e r s as reviewed by Hass (1981). C o g n i t i v e response theory i s a b l e to account f o r some of the e f f e c t s of message s t r u c t u r e on p e r s u a s i o n . A message i s more p e r s u a s i v e i f i t disarms the r e c i p e n t ' s counterarguments e a r l y i n the message and i f i t avoids suggesting new counterarguments u n t i l l a t e i n the message, or not at a l l . An i m p l i c i t r e f u t a t i o n at the s t a r t of the message w i l l have a g r e a t e r e f f e c t on p e rsuasion with a high c r e d i b l i t y source as the r e c i p i e n t i s l e s s l i k e l y to counterargue. (Hass, 1981) I I . CONGRUITY THEORY Th i s theory suggests that we tend to maintain the same a t t i t u d e toward a person as toward t h e i r p o s s e s s i o n s and a c t i o n s . I f a person i s f e l t to be a high c r e d i b i l t i y source, but we d i s l i k e h i s message ( i e a c t i o n s ) , our a t t i t u d e s toward him are now i n an unbalanced s t a t e . T h i s unbalance or incongruence, i s r e s o l v e d by : 1) a change in a t t i t u d e toward the message v i a acceptance or r e i n t e r p r e t a i o n of the message; 2) a change i n a t t i t u d e toward the 57 communicator; 3) a change i n the p e r c e i v e d r o l e of the communicator i n c r e a t i n g the message. These changes r e s t o r e balance or c o n g r u i t y r e c e i v e r ' s a t i t u d e s toward the communicator communicator's a c t i o n s . (Hovland et a l . , 1953) The b a s i c p r i n c i p l e s t a t e s : "Whenever two si g n s are r e l a t e d by an a s s e r t i o n the mediating c h a r a c t e r i s t i c of each s h i f t s toward congruence with that c h a r a c t e r i s t i c of the other , the magnitude of the s h i f t being i n v e r s e l y p r o p o r t i o n a l to the i n t e n s i t i e s of the i n t e r a c t i n g r e a c t i o n s . " (p 200, Osgood et al.,1957). Congruity p r i n c i p l e does not take i n t o account a l l the v a r i a b l e s t h a t i n f l u e n c e a t t i t u d e change, but, i t does cover the most s i g n i f i c a n t with r e s p e c t to the d i r e c t i o n of change ( f a v o u r a b l e / unfavourable) and the maginitude of change ( r e l a t i v e amount). The v a r i a b l e s covered i n c l u d e : 1) the e x i s t i n g a t t i t u d e of a su b j e c t toward a source; 2) e x i s t i n g a t t i t u d e s toward a concept; 3) the value of the as s e r t o n r e l a t i n g them. The t y p i c a l s i t u a t i o n f o r a t t i t u d e change i s where a source makes some e v a l u a t i v e statement or a s e r t i o n about some o b j e c t or concept i n a message that i s r e c e i v e d and decoded by a r e c e i v e r . The source and concept each have a s i g n of +, -, or 0, meaning that the message r e c e i v e r i s fa v o u r a b l e , unfavourable or n e u t r a l among a and the 58 toward the o b j e c t . , The a s s e r t i o n can be a s s o c i a t i v e , (that i s p o s i t i v e ) as i n 'A i s B', or d i s a s s o c i a t i v e , as i n 'A i s not B'. The a s s e r t i o n r e s u l t s i n A and B being l i n k e d t o g e t h e r . "Whenever two sign s are r e l a t e d by an a s s e r t i o n , they are congruent to the extent that the mediating r e a c t i o n s are e q u a l l y i n t e n s e , e i t h e r i n the same (compatible) d i r e c t i o n , i n the case of a s s o c i a t i v e a s s e r t i o n s , or i n opp o s i t e ( r e c i p r o c a l l y a n t a g o n i s t i c ) d i r e c t i o n s i n the case of d i s s o c i a t i v e a s s e r t i o n s . " (p 203, Osgood et a l . , 1957) Congruity occurs n a t u r a l l y i f : 1) both s i d e s are e q u a l l y i n t e n s e i n the same compatible d i r e c t i o n ; 2) op p o s i t e i n t e n s e s i g n s i n a d i s s o c i a t i v e a s s e r t i o n 3) each s i d e i s e q u a l l y i n t e n s e , but i n the oppo s i t e d i r e c t i o n eg., a +source d i s s o c i a t e s a - o b j e c t , or a -source d i s s o c i a t e s a +object; Congruity i s maintained by s h i f t i n g e v a l u a t i o n s of the source and or the o b j e c t i n the f o l l o w i n g s i t u a t i o n s : 1) when both s i g n s are e q u a l l y i n t e n s e , but d i s s o c i a t e d , the p o i n t of c o n g r u i t y i s r e c i p r o c a l l y a n t a g o n i s t i c , that i s , i n oppo s i t e d i r e c t i o n s and e v a l u a t i o n of the source or the o b j e c t w i l l s h i f t with whichever i s the most inte n s e s h i f t i n g the l e a s t and whichever i s the l e a s t i n t e n s e s h i f t i n g the most. 59 2) when sign s o p p o s i t e i n i n t e n s i t y are r e l a t e d by an a s s o c i a t i v e a s s e r t i o n ; 3) a n e u t r a l s i g n i s l i n k e d by an a s o c i a t i v e a s s e r t i o n to a +ve s i g n , the n e u t r a l s i g n becomes more p o s i t i v e 4) when a n e u t r a l s i g n i s l i n k e d by a d i s s o c i a t i v e a s s e r t i o n to a -ve s i g n , the n e u t r a l p o s i t i o n becomes more p o s i t i v e eg. "I am a g a i n s t s i n " . (Osgood et a l . , 1957). Con g r u i t y p r i n c i p l e holds that an image or meaning depends upon other concepts with which i t i s a s s o c i a t e d and thus i s s u b j e c t to p e r p e t u a l change (Anderson and Clevenger, 1963). "According to c o n g r u i t y theory, when a source advocates a p o s i t i o n , there i s a tendancy f o r the r e c i p i e n t ' s e v a l u a t i o n of both the source and the p o s i t i o n to s h i f t to a p o i n t of e q u i l i b r i u m or c o n g r u i t y , and those s h i f t s are i n v e r s e l y r e l a t e d to the extremity of the i n i t i a l e v a l u a t i o n T h i s theory makes p r e d i c t i o n s r e g a r d i n g both the d i r e c t i o n and the amount of change that w i l l occur" (p.146, Hass, 1981). Whenever a source and an a t t i t u d e (toward an o b j e c t , person, or matter) are l i n k e d , p r e s s u r e s toward a t t i t u d i n a l congruence a r i s e . I f a source expresses a f a v o u r a b l e a t t i t u d e on a t o p i c , congruence occurs when the r e c i p i e n t holds the same a t t i t u d e toward both the source and the t o p i c . I f the source makes an unfavouravble a s s e r t i o n about the t o p i c , congruence occurs when the r e c i p i e n t holds a t t i t u d e s toward the source and the t o p i c that are e q u a l l y i n t e n s e , but o p p o s i t e i n d i r e c t i o n . 6 0 The theory f u r t h e r p r e d i c t s that i f a t t i t u d e change i s necessary to r e s t o r e c o n g r u i t y , then both one's a t t i t u d e toward the source and one's a t t i t u d e toward the t o p i c w i l l change, with the one that i s more extreme changing l e s s . "More p r e c i s e l y , the degree of change of one's a t t i t u d e toward the source or the t o p i c w i l l be i n v e r s e l y p r o p o r t i o n a l to the i n i t i a l p o l a r i t y of those a t t i t u d e s i . e . d i s t a n c e from the n e u t r a l p o i n t " (p 147, Hass, 1981). Congruity theory makes the reasonable-sounding p r e d i c t i o n that l i n k i n g a source with an a t t i t u d e p r o p o s i t i o n may change a message r e c i p i e n t ' s view of the source as w e l l as t h e i r a t t i t u d e on an . i s s u e . Other t h e o r i e s do not allow f o r the r e c i p i e n t ' s view of the source to change in a d d i t i o n t o or i n s t e a d of changes in a t t i t u d e , except f o r c o g n i t i v e dissonance theory. The author s t a t e s , however, that i t i s probably more l i k e l y that the a t t i t u d e toward the t o p i c would change r a t h e r than the a t t i u d e toward the source (Hass, 1981). I I I . SELF PERCEPTION THEORY S e l f p e r c e p t i o n theory, accounts f o r the s i t u a t i o n where an i n d i v i d u a l ' s own experience or behavior, as w e l l as the communication source, are the b a s i s f o r a t t i t u d i n a l judgements. T h i s theory e x p l a i n s why a low c r e d i b i l i t y source causes g r e a t e r persuasion than a high c r e d i b i l i t y source a f t e r i n d i v i d u a l s have v o l u n t a r i l y complied with the message request, or v o l u n t a r i l y exposed themselves to the message. By i n d i c a t i n g t o r e c i p i e n t s that t h e i r complying behavior was not v o l u n t a r y , the r e c i p i e n t may focus on the c a u s a l 61 antecedants of the message, such as the message content, evidence or arguments. But, i f the c h o i c e of compliance i s v o l u n t a r y , i n d i v i d u a l s focus on the causes of t h e i r behavior, r a t h e r than on the message i t s e l f . I f , i n t h i s s i t u a t i o n , the source i s h i g h l y c r e d i b l e , the v o l u n t a r y compliance i s a t t r i b u t e d t o : a) A p o s i t i v e a t t i t u d e toward the behavior; OR, b) The f a c t that they were s o l i c i t e d by a h i g h l y c r e d i b l e source. With two r i v a l e x p l a n a t i o n s f o r t h e i r behavior, u n c e r t a i n t y about the reason f o r behavior and hence a t t i t u d e i s c r e a t e d . However, i n the case of a low c r e d i b i l i t y source, the source i s no longer a p l a u s i b l e reason f o r the r e s u l t i n g behavior, and so there i s only one e x p l a n a t i o n . Thus, there i s more c e r t a i n t y r e g a r d i n g the cause of behavior and hence a stronger a t t i t u d e w i l l r e s u l t . In other words, r i v a l e x p l a n a t i o n s of behavior cause u n c e r t a i n t y r e g a r d i n g the cause of behavior and l e s s persuasion w i l l r e s u l t . When there i s only one reason f o r behavior, there i s c e r t a i n t y r e g a r d i n g the cause, and a s t r o n g a t t i t u d e w i l l r e s u l t i e . , more pe r s u a s i o n w i l l take p l a c e . ( S t e r n t h a l and D h o l a k i a , 1977) 62 IV. ATTRIBUTION THEORY A t t r i b u t i o n theory i s so named because i t d e a l s with a t t r i b u t i n g the cause of behaviour to e i t h e r i n t e r n a l reasons or e x t e r n a l reasons. People come to know t h e i r a t t i t u d e s by i n f e r r i n g from t h e i r own behaviour and the circumstances i n which t h i s behaviour o c c u r s . When behaviour i s j u s t i f i e d by i n t e r n a l reasons, the i n d i v i d u a l i s more l i k e l y to be c e r t a i n about h i s / h e r a t t i t u d e toward the the o b j e c t of h i s / h e r behaviour. For example, behaviour such as s i g n i n g a p e t i t i o n ( S t e r n t h a l et a l . , 1978b). " I signed the p e t i t i o n , t h e r e f o r e I must b e l i e v e i t . " Even g r e a t e r c e r t a i n t y about one's a t t i t u d e occurs when a b e h a v i o r a l circumstance i s present that normally i n h i b i t s the performance of the behaviour, but t h i s time does not. Behaviour i s then j u s t i f i e d even more by i n t e r n a l reasons and a s t r o n g a t t i t u d e toward the o b j e c t of the behaviour i s a c q u i r e d . However, i f circumstances p r o v i d e r i v a l j u s t i f i c a t i o n s f o r behaviour, the i n d i v i d u a l d i s c o u n t s i n t e r n a l causes and i s u n c e r t a i n as to the cause of the behaviour and i s t h e r e f o r e u n l i k e l y to have st r o n g a t t i t u d e s toward the o b j e c t . In a t t r i b u t i o n terms, a h i g h c r e d i b l i t y source causes people to d i s c o u n t i n t e r n a l reasons f o r t h e i r behavior and t h e r e f o r e f a i l t o c o n s o l i d a t e a favourable a t t i t u d e . A low c r e d i b l i t y source causes people to augment i n t e r n a l reasons f o r t h e i r behavior and t h e r e f o r e f e e l c e r t a i n about t h e i r a t t i t u d e s and c o n s o l i d a t e a favourable a t t i t u d e ( S t e r n t h a l et a l . , 1978b). The i n t e r a c t i o n e f f e c t s of message and source c r e d i b i l i t y 63 are e x p l a i n e d by a t t r i b u t i o n theory. An unexpected p o s i t i o n from a source i n c r e a s e s the r e c e i v e r ' s c e r t a i n t y t h a t the message i s tr u e and persuasion i s augmented. When the expected p o s i t i o n i s advocated, the r e c e i v e r i s u n c e r t a i n whether the message r e p r e s e n t s the t r u t h or j u s t the person's viewpoint. Persuasion w i l l then depend on c r e d i b i l t y . A high c r e d i b i l t y source i s l i k e l y to induce the b e l i e f that the message i s v a l i d , whereas a low c r e d i b i l i t y source i s l i k e l y to cause d i s b e l i e f i n the v a l i d i t y of the message and l e s s p e r s u asion w i l l occur. Thus, i f a r e c e i v e r expects a hig h c r e d i b i l t y source to make statements c o n s i s t e n t with h i s / h e r own b e l i e f s , i n c r e a s i n g the message d i s c r e p a n c y should enhance a t t i t u d e change. On the other hand, a low c r e d i b l i t y source i s expected to make d i s c r e p a n t c l a i m s , which are l i k e l y to be thought due to the source's b i a s and t h e r e f o r e have l i t t l e e f f e c t on a t t i t u d e change. A low c r e d i b i l i t y source s t a t i n g a moderately d i s c r e p a n t p o s i t i o n r e s u l t s i n the message being viewed as accurate and i s t h e r e f o r e r e l a t i v e l y p e r s u a s i v e . If a t h r e a t i s unexpected, f o r example i f i t came from a high c r e d i b i l l i t y source, t h i s source w i l l cause g r e a t e r p e r s u a s i o n , e s p e c i a l l y when the t h r e a t i s s u b s t a n t i v e . Since u n f a m i l i a r evidence or an incongruous p o s i t i o n are more unexpected when they o r i g i n a t e from a low c r e d i b i l i t y source, the theory says that there w i l l be no source e f f e c t . I n d i v i d u a l d i f f e r e n c e s are a l s o accounted f o r by t h i s t h eory. People with an e x t e r n a l locus of c o n t r o l are more l i k e l y to r e l y on source c r e d i b i l i t y i n making c a u s a l 64 a t t r i b u t i o n s and t h e r e f o r e be more persuaded by a high c r e d i b i l i t y source. I n t e r n a l l o c u s of c o n t r o l people do not respond to the source e f f e c t . High a u t h o r i t a r i a n people r e l y on the dominant cue and and low a u t h o r i t a r i a n s employ both the message and source cues. A t t r i b u t i o n theory d e s c r i b e s the i n f e r e n t i a l work i n d i v i d u a l s perform i n i n t e r p r e t i n g and s e l e c t i n g p e r s u a s i v e cues. However, i t does not d e s c r i b e the mechanism of a c i t v e i n f o r m a t i o n p r o c e s s i n g which i s d e s c r i b e d by c o g n i t i v e response theory. T h i s combinaton of c o g n i t i v e response and a t t r i b u t i o n t h e o r i e s , a c c o r d i n g to S t e r n t h a l et a l . (1978b) provide complimentary and r e l a t e d e x p l a n a t i o n s of how the communication process works. T h i s combined process can be summarized i n the f o l l o w i n g paragraphs. Strong i n i t i a l o p i n i o n s are s t o r e d i n the short term memory and the message , upon e n t e r i n g the short term memory, t r i g g e r s the r e t r e i v a l of thoughts from the long term s t o r a g e . T h i s thought r e t r e i v a l process i s mediated by source c r e d i b i l i t y . A high c r e d i b i l t y source i n h i b i t s counteragrguing i f the r e c e i v e r has a negative i n i t i a l o p i n i o n toward the message content. A low c r e d i b i l t i y source s t i m u l a t e s support arguments i f the r e c e i v e r has a p o s i t i v e i n t i t i a l o p i n i o n towards the message content. There i s no source e f f e c t i f the i n i t i a l o p i n i o n i s n e u t r a l and i n s t e a d , behaviors a s s o c i a t e d with the message are examined. If source c r e d i b i l i t y causes a r e c i p i e n t to di s c o u n t INTERNAL reasons f o r behavior, few c o g n i t i v e responses are 6 5 r e t r e i v e d from the short term memory and there i s l i t t l e p e r s u a s i o n . I f source c r e d i b i l t i y causes a r e c i p i e n t to a t t r i b u t e the cause of behavior to INTERNAL reasons, t h i s t r i g g e r s the r e t r e i v a l of p o s i t i v e thoughts from the long term memory and p e r s u a s i o n o c c u r s . F a i l u r e to comply with the advocacy of a h i g h c r e d i b i l i t y source leads to counterarguments, whereas, compliance with a low c r e d i b i l t i y source s t i m u l t e s suppport arguments , l e a d i n g to c o n s o l i d a t i o n of an a t t i t u d e which w i l l serve as the i n i t i a l o p i n i o n i n subsequent s i t u a t i o n s ( S t e r n t h a l , et a l . , 1978b). V. COGNITIVE DISSONANCE THEORY As reviewed by Hass (1981), F e s t i n g e r ' s c o g n i t i v e dissonance theory p r e d i c t s t h a t , under c o n d i t i o n s where a r e c i p i e n t v o l u n t a r i l y chooses to expose himsel f to a p e r s u a s i v e communication, a source w i l l produce more a t t i t u d e change as the r e c i p i e n t ' s d i s l i k e f o r a source i n c r e a s e s . T h i s i s due to the r e c i p i e n t j u s t i f y i n g the c h o i c e to h i m s e l f or h e r s e l f . For example, i f the source i s d i s r e p u t a b l e , or u n l i k e d , then the i n d i v i d u a l can not j u s t i f y the d e c i s i o n to l i s t e n to the message on the b a s i s of the source. As a r e s u l t , the i n d i v i d u a l j u s t i f i e s the d e c i s i o n to l i s t e n by b e l i e v i n g t hat the message i t s e l f was worth l i s t e n i n g to and w i l l t h e r e f o r e be more i n f l u e n c e d by i t (Hass, 1981). T h i s theory has r e c e i v e d experimental support i n a number of s t u d i e s i n the s i x t i e s , but there has been some c r i t i c i s m of the l i m i t a t i o n s of t h i s theory. These a r e : 66 1) s e v e r a l i n v e s t i g a t o r s show that the theory i s i n c o r r e c t r e g a r d i n g the process by which c r e d i b i l i t y mediates i n f l u e n c e or persuausion; 2) another theory, a t t r i b u t i o n theory, e x p l a i n s the same e f f e c t s and i t a l s o d e a l s with a t t i t u d e - c o n s i s e n t behavior s i t u a t i o n s t h a t c o g n i t i v e dissonance does not ( S t e r n t h a l and D h o l a k i a , 1977). VI. LEAST EFFORT HYPOTHESIS Another theory that has not r e c e i v e d much experimental support i s the l e a s t e f f o r t h y p o t h e s i s . T h i s theory, as reviewed by Hass (1981), suggests that counterarguing and d e r o g a t i o n of the source are a l t e r n a t i v e means of p r e v e n t i n g p e r s u a s i o n and the r e c i p i e n t enagages i n whichever i s the l e a s t e f f o r t . A low c r e d i b i l t y source i s e a s i e r to r e j e c t or degrade than to counterargue with the message content. Whereas, with a h i g h c r e d i b i l i t y source, i t i s much e a s i e r to counterargue with the message content than degrade the source. T h i s i s o p p o s i t e to c o g n i t i v e response theory as i t has a low c r e d i b l i t y source causing l e s s counterargumentation and a high c r e d i b i l t i y source causing more. Other t h e o r i e s w i t h i n the f i e l d of psychology, such as Bas i c Antimony (Hass, 1981) and Theory of Reasoned A c t i o n ( F i s h b e i n , 1975) do e x i s t , but, are not adddressed i n t h i s paper. 6 7 IV. RELATED STUDIES There are s e v e r a l s t u d i e s of source c r e d i b i l t i y that were p a r t i c u l a r l y i n t e r e s t e d i n determining the i n f l u e n c e of the r e c e i v e r ' s i n i t i a l a t t i t u d e on the e f f e c t i v e n e s s of source c r e d i b i l i t y , and the d i s r e p a n c y of the message from the r e c e i v e r ' s p o i n t of view. T h i s i s s i m i l a r to the design of the present study. A study on a t t i t u d e s towards American involvement i n Vietnam, s p l i t the audience i n t o two groups, one moderately negative and the other extremely n e g a t i v e . These two groups were then exposed to a pro-involvement message a t t r i b u t e d to authors that v a r i e d i n t h e i r c r e d i b i l i t y . The r e s u l t s showed t h a t : 1) i n i t i a l a t t i t u d e i t s e l f - d i d not d i f f e r e n t i a t e a f f e c t the s u s c e p t i b i l i t y of the s u b j e c t s to p e r s u a s i o n ; 2) the p e r s u a s i v e manipulation was indeed e f f e c t i v e ; 3) source c r e d i b l i t y was not s i g n i f i c a n t as a main e f f e c t , but i t d i d i n t e r a c t with the i n i t i a l a t t i t u d e at the a= .05 l e v e l ; 4) the degree of involvement (knowledge and i n t e r e s t i n the t o p i c ) was s i g n i f i c a n t as a main e f f e c t and i n i n t e r a c t i o n with the i n i t i t a l a t t i t u d e . I t was concluded that a h i g h l y c r e d i b l e source was more 68 pe r s u a s i v e than a l e s s c r e d i b i b l e source, only f o r those s u b j e c t s who h e l d extreme i n i t i a l a t t i t u d e s (McGuinies, 1973). T h i s i s supported by e a r l i e r work by Bochner and Insko (1966). In a d d i t i o n , a t t i t u d e change was found to be g r e a t e s t f o r those wth extreme i n i t i a l a t t i t u d e , but low involvement (McGuinies,1973). More recent work s t u d i e d the p e r c e p t i o n s of the c r e d i b i l i t y of message sources who e i t h e r agreed or d i s a g r e e d with r e c e i v e r s of w r i t t e n messages (Jurma, 1981) . R e s u l t s i n d i c a t e d that message sources were judged e q u a l l y on the t r u s t w o r t h i n e s s f a c t o r , r e g a r d l e s s of whether the w r i t t e n message agreed or d i s a g r e e d with that of the r e c i p i e n t . In a d d i t i o n , low r a t i n g s f o r c o - o r i e n t a i o n and e x p e r t i s e were given f o r the message that d i s a g r e e d with the r e c i p i e n t ' s view. As long as a s u b s t a t i v e message i s presented, the d i s a g r e e i n g source can seem reasonably trustworthy and q u i t e c h a r i s m a t i c (Jurma, 1981). No measurement of p e r s u a s i o n was made. Sh a f f e r et a l . (1981), i n a study of message di s c r e p a n c y r e g a r d i n g textbook p r i c e s , found that those s u b j e c t s exposed to a h i g h l y d i s c r e p a n t message r e v e r s e d t h e i r estimates of a reasonable p r i c e i n c r e a s e , the maximum p r i c e i n c r e a s e a c c e p t a b l e and the minimum p r i c e increase that was unacceptable. The r e s e a r c h e r s concluded that a simple i n f o r m a t i o n a l (vs pe r s u a s i v e ) communication that was s u f f i c i e n t l y extreme, induced changes i n the a t t i t u d i n a l c o n s t r u c t s to which i t was most d i r e c t l y r e l e v a n t ( S h a f f e r et a l . , 1981). T h i s s i t u a t i o n may be d i f f e r e n t f o r a more e m o t i o n a l l y charged i s s u e such as food 69 a d d i t i v e s , or i n the case of a fad or a c u l t u r a l t r u i s m . A study by Wheeless (1974), addressed a r e s e a r c h question s i m i l a r to that posed by t h i s r e s e a r c h e r : "How much v a r i a n c e in post a t t i t u d e i n t e n s i t y can be accounted f o r by p r i o r a t t i t u d e and c r e d i b i l i t y ?" (p.278, Wheeless, 1974) . Although the a c t u a l purpose of the Wheeless res e a r c h was somewhat d i f f e r e n t from the present study, the r e s u l t s are of i n t e r e s t . In the r e g r e s s i o n a n a l y s i s i t was found that 61% to 66% of the v a r i a n c e i n post a t t i t u d e i n t e n s i t y c o u l d be accounted f o r by the e x i s t i n g t h e o r e t i c a l c o n s t r u c t s i n a t t i t u d e ( a t t i t u d e i n t e n s i t y , importance and involvement) and source c r e d i b i l i t y (competence, s o c i a l b i l i t y , e x t r o v e r s i o n , composure and c h a r a c t e r ) . A message t o p i c , "The Space Programme", was chosen on the b a s i s that i t would maximize the v a r i a b l i t y of i n t e n s i t y , importance and involvement. Sources were d e s c r i b e d as being high, moderate or low i n c r e d i b i l i t y . In the l i n e a r r e g r e s s i o n , 61% of the v a r i a n c e was accounted f o r , with p r e - a t t i t u d e i n t e n s i t y accounting f o r 51% and a t t i t u d e importance, source competence and source s o c i a b i l i t y accounting f o r the remaining 10% of the v a r i a n c e . I t i s of i n t e r e s t to note that three of the f i v e s c a l e s used by Wheeless to measure a t t i t u d e i n t e n s i t y were the same as those used i n the present study to measure a t t i t u d e . The f i e l d of n u t r i t i o n education has looked at a t t i t u d e change t h e o r i e s , but, as yet there has been no r e s e a r c h on the r o l e of source i n a c h i e v i n g t h i s change (Sims, 1981; Olson and 7 0 G i l l e s p i e , 1981). In terms of the problem with food m i s i n f o r m a t i o n , no s t u d i e s have addressed the r o l e of source in a l e v i a t i n g the problem. 71 I I I . METHODOLOGY I. POPULATION I d e a l l y , the t a r g e t p o p u l a t i o n to which any e d u c a t i o n a l , c o u n t e r - m i s i n f o r m a t i o n would be addressed i s the "average consumer". Anyone making food c h o i c e s i n the marketplace, would be a p o t e n t i a l t a r g e t f o r r e l i a b l e i n f o r m a t i o n . T h i s t a r g e t p o p u l a t i o n was not r e a d i l y a v a i l a b l e however, and i n s t e a d , an a c c e s s i b l e p o p u l a t i o n was u t i l i z e d . I I . THE SAMPLE A convenient, non-random sample was used f o r t h i s study . Nine c l a s s e s of summer students e n r o l l e d i n e d u c a t i o n a l psychology courses at the U n i v e r s i t y of B r i t i s h Columbia completed the survey d u r i n g the month of August, 1982. Approximately 75 were female and 50 male. Many were teachers, and ages ranged approximately from 25 to 45 ye a r s . No socio/demographic i n f o r m a t i o n was taken. 132 surveys were completed,with 7 being r e j e c t e d f o r incomplete or erroneous responses. The r e s e a r c h e r gave the same 5-minute i n t r o d u c t i o n and set of d i r e c t i o n s to each c l a s s . Every attempt was made to minimize any e f f e c t s of t e s t a d m i n i s t r a t i o n on the outcome. No attempt was made to hide the purpose of the survey. (See Appendix C ) . The t e s t b o o k l e t and hence the treatment v a r i a b l e source, was randomly d i s t r i b u t e d among the students. 72 I I I . THE INSTRUMENTS Two Presurveys and a Main Survey were conducted. Presurvey One determined which sources should be used i n the main survey, where a pro-food a d d i t i v e message i s a t t r i b u t e d to these sources. The d i f f e r e n t sources c o n s t i t u t e d the treatment v a r i a b l e s . Presurvey Two determined which statements about food a d d i t i v e s should be used i n the main survey to measure the a t t i t u d e s and b e l i e f s of the respondants about food a d d i t i v e s . The Main Survey was c o n t a i n e d i n a booklet with an a t t i t u d e and b e l i e f measure; a pro-food a d d i t i v e message a t t r i b u t e d to one of the three sources chosen from Presurvey One, or no source i n the case of the c o n t r o l group; and a post-measure of b e l i e f i n the pro-food a d d i t i v e message. I. PRE-SURVEY ONE, CHOICE OF SOURCES Within the r e s e a r c h design model, a number of p o t e n t i a l sources of food a d d i t i v e i n f o r m a t i o n were r e q u i r e d to serve as treatment v a r i a b l e s . From the e x t e n s i v e l i t e r a t u r e on f a c t o r s that measure source c r e d i b i l i t y , the recent p u b l i c a t i o n by McCroskey, (1981) was used to develop the meaurement instrument. McCroskey's review of r e s e a r c h i n the f i e l d of source c r e d i b i l i t y concluded that there were only two f a c t o r s that best measured source c r e d i b i l i t y : 1) p e r c e i v e d source competence and 2) p e r c e i v e d source c h a r a c t e r . The t h i r d t h e o r e t i c a l f a c t o r of source c r e d i b i l i t y , i n t e n t i o n , i s p r a c t i c a l l y measured by the c h a r a c t e r f a c t o r (McCroskey, 1981). The s c a l e u t i l i z e d i n Presurvey One c o n s i s i t e d of s i x 73 seven- p o i n t s c a l e s anchored by s i x b i p o l a r a d j e c t i v e p a i r s . Three of the p a i r s measured c h a r a c t e r and three measured competence The s c a l e s used to measure competence and ch a r a c t e r are presented i n Table 1 . Table I - Source C r e d i b i l i t y Measurement S c a l e s CHARACTER honest - - - - - - - dishonest trustworthy - - - - - - - untrustworthy sympathetic - - - - - - - unsympathetic COMPETENCE competent - - - - - - - incompetent i n e x p e r i e n c e d - - - - - - - experienced t r a i n e d - - - - - - - u n t r a i n e d These a d j e c t i v e p a i r s have been reported to y i e l d r e l i a b l e and v a l i d s cores on these f a c t o r (McCroskey 1966). S e v e r a l p o t e n t i a l sources of i n f o r m a t i o n about food a d d i t i v e s t h a t were a v a i l a b l e t o the p u b l i c were r a t e d to determine which of the sources should be used i n the main survey as the sources of the pro-food a d d i t i v e message ( i e . tre a t m e n t s ) . These p o t e n t i a l sources were: 1) a consumer r e p o r t e r ( C R . ) 2) a government spokesman (G.S.) 3) a medical doctor (M.D.) 4) a food s c i e n t i s t (F.S.) 74 5) an annonymous r e p o r t e r (A.R.) 6) a n u t r i t i o n i s t (Nutr.) 7) a h e a l t h food advocate (H.F.A.) Twenty-two c o p i e s of Presurvey One were randomly d i s t r i b u t e d among students w i t h i n the Department of Food Science at UBC. Students were asked to choose which word i n the a d j e c t i v e p a i r best d e s c r i b e d t h e i r f e e l i n g s about the source of inf o r m a t i o n on food a d d i t i v e s . See Appenndix A f o r a c t u a l q u e s t i o n a i r e used. Table II -Scores and R e l i a b i l i t y of Source C r e d i b i l i t y Measure Source Mean Std . Competence Character Hoyt S.E.M. Score Dev. Score Score R e l . M.D. 31.45 5.51 5.10 5.40 0.87 1 .84 F.S. 34.91 3.80 6.20 5.43 0.65 2.05 C R . 28.05 6.48 4.43 4.93 0.87 2.14 G.S. 25.45 4.01 4.46 4.03 0.49 2.60 A.R. 22.09 4.57 3.33 4.03 0.79 1 .93 Nutr. 39.64 4.36 6.16 5.73 0.74 2.04 H.F.A. 24.64 3.68 3.70 4.53 0.51 2.35 The LERTAP computer a n a l y s i s was conducted to generate an o v e r a l l mean c r e d i b i l i t y score, mean competence score and mean c h a r a c t e r score , as w e l l as the Hoyt R e l i a b i l i t y C o e f f i c i e n t 75 f o r the whole model and the standard e r r o r of measurement f o r the whole model. These v a l u e s are presented i n Table I I . From Table I I , i t can be seen that the top three mean scores f o r c r e d i b i l i t y a r e : 1. N u t r i t i o n i s t (Nutr.) 2. Food S c i e n t i s t (F.S.) 3. M e d i c a l Doctor (M.D.) The mean c h a r a t e r scores were p l o t t e d a g a i n s t the mean competence scores f o r each source (Figure 1). The top three sources were then chosen f o r i n c l u s i o n i n the message p a r t of the Main Survey. 76 F i g u r e 1 - C r e d i b i l i t y R a t i n g s of Sources of Food A d d i t i v e I n f o r m a t i o n Nutritionist t i p 0od Scientist CD U o 5 in c rt Government Spokesman • Medical Doctor • Consumer Reporter CD u c <D 4-1 CD P< o o u Annonymous Reporter » « Health Food Advocate * 1 2 Character (Mean Score) 77 From F i g u r e 1., i t can be seen that the food s c i e n t i s t , the n u t r i t i o n i s t and the medical doctor were the most c r e d i b l e as r a t e d by the small sample of food s c i e n c e students. The n u r i t i o n i s t r e c e i v e d the top mean score, the consumer r e p o r t e r ( C R . ) had the mid score (28.05) and the annonymous r e p o r t e r (A.R.) was scored the lowest ( l e a s t c r e d i b l e ) , with a mean score of 22.09 over both the c h a r a c t e r and competence measures. The Hoyt R e l i a b i l i t y C o e f f i c i e n t i s an estimate of the amount of v a r i a t i o n i n r a t i n g s on the s c a l e s that i s due to i n d i v i d u a l d i f f e r e n c e s , t a k i n g i n t o account v a r i a t i o n s due to the s p e c i f i c nature of the items and the unaccounted f o r v a r i a t i o n , or e r r o r . I f the s c a l e i s h i g h l y r e l i a b l e , the source of v a r i a t i o n due to i n d i v i d u a l s i s h i g h compared to the other sources of v a r i a t i o n . A value of .74 or g r e a t e r i s d e s i r e a b l e (Nelson, 1978). The Hoyt R e l i a b i l i t y C o e f f i c i e n t f o r the Food S c i e n t i s t does not meet t h i s requirement. However, i t was f e l t t h a t the high score outweighed t h i s c r i t e r i o n . Most s t u d i e s comparing c r e d i b i l i t y chose a h i g h , medium and low c r e d i b i l i t y source to determine i f there was any d i f f e r e n c e between the three types, but i n t h i s case, the i n t e r e s t i s i n determining i f the most c r e d i b l e sources are indeed e f f e c t i v e . II . PRE-SURVEY 2j_ SELECTION OF STATEMENTS The purpose of t h i s survey was to determine which statements about food a d d i t i v e s should be i n c l u d e d i n the main survey to measure a t t i t u d e s and b e l i e f s about food a d d i t i v e s . I t was hypothesized, based on the l i t e r a t u r e , that i n d i v i d u a l 78 a t t i t u d e s may i n f l u e n c e b e l i e f i n a pro-food a d d i t i v e message (Hass, 1981; e t c . ) . In a d d i t i o n , a c o v a r i a t e : b e l i e f i n the statements about food a d d i t i v e s was i n c l u d e d t o in c r e a s e the p r o b a b i l i t y of d e t e c t i n g a s t a t i s t i c a l l y s i g n i f i c a n t i n t e r a c t i o n between a t t i t u d e toward food a d d i t i v e s and the source of the message (Maxwell and Delaney, 1981). Twenty-two statements about food a d d i t i v e s were generated from p r e v i o u s surveys that measured food a d d i t i v e a t t i t u d e s (Boocock, 1978, Duffek,l978; Knox and S c h r e i b e r , 1980; Martinsen and McCullough, 1977; and Z i b r i k et a l , 1981); from l i t e r a t u r e documentation of m i s i n f o r m a t i o n ( F r a n c i s , 1979; C l y d e s d a l e , 1980; H a l l , 1973, 1977); and from expert a d v i c e and p e r s o n a l experience. These statements are l i s t e d i n Table I I I . These statements covered a range of a t t i t u d e s ( p o s i t i v e , n e u t r a l and negative) and a range of extremes ( s t r o n g , q u i t e s t r o n g , s l i g h t l y s t r o n g and weak) (Tables IV and V ). Respondents were asked to determine the r e l a t i v e p o s i t i o n of each statement on a seven-point s c a l e i n d i c a t i n g how s t r o n g l y p o s i t i v e or how s t r o n g l y n e g ative the statements were f e l t to be. The statements were i n the format of an a s s e r t i o n made d i r e c t l y about the sub j e c t - food a d d i t i v e s . The format, X > Y, where X r e p r e s e n t s the subject of the a s s e r t i o n ; > r e p r e s e n t s the a s s e r t i o n and Y the o b j e c t t o which the su b j e c t i s l i n k e d , was used. T h i s format, X > Y , attempts to reduce e x t r a thoughts that might r e s u l t from m i s i n t e r p r e t a t i o n (Osgood et a l . , 1957). 79 T h i r t e e n graduate and summer students i n the Department of Food Science at The U n i v e r s i t y of B r i t i s h Columbia completed the survey i n May of 1982. Two r e t u r n s were r e j e c t e d f o r i n c o r r e c t completion. With respondents having a food s c i e n c e background completing the survey, statements that w r e l a t i v e l y pro-food a d d i t i v e were expected to be i n d i c a t e d as being p o s i t i v e , while those that were r e l a t i v e l y a n t i - f o o d a d d i t i v e or untrue i n nature would be marked as n e g a t i v e . See Appendix A f o r a c t u a l q u e s t i o n a i r e used. 80 T a b l e I I I - Food A d d i t i v e Statements Used i n P r e - s u r v e y #2 1. Food a d d i t i v e s do not improve food q u a l i t y . 2 Food a d d i t i v e s c a r e s a r e a b s o l u t e nonsense. 3. Food a d d i t i v e s cannot be l i n k e d t o human d e a t h . 4. Food a d d i t i v e e f f e c t s on human h e a l t h a r e e x t r e m e l y s p e c u l a t i v e . 5. Food a d d i t i v e s a r e a s e r i o u s r i s k t o h e a l t h . 6. Food a d d i t i v e s a r e s e n s a t i o n a l i z e d i n the media. 7. Food a d d i t i v e t e s t i n g i s i n a d e q u a t e . 8. Food a d d i t i v e s a r e h a r m l e s s . 9. Food a d d i t i v e s cause d i s e a s e . 10. Food a d d i t i v e use i s out of c o n t r o l . 1 1 . Food a d d i t i v e s s h o u l d be a v o i d e d 12. Food a d d i t i v e s a r e used f o r company p r o f i t s o n l y . 13. Food a d d i t i v e s d i s g u i s e i n f e r i o r p r o d u c t s . 14. Food a d d i t i v e s a r e r e a l l y o n l y a monor r i s k t o h e a l t h . 15. Food a d d i t i v e s a r e s a f e f o r c h i l d r e n 16. Food a d d i t i v e s mean everyone has enough t o e a t . 17. Food a d d i t i v e s s h o u l d be e l i m i n a t e d from f o o d . 18. Food a d d i t i v e s a r e p o t e n t i a l l y h a z a r d o u s . 19. Food a d d i t i v e s a r e a d e q u a t e l y c o n t r o l l e d by food r e g u l a t i o n s . 20. Food a d d i t i v e t e s t i n g e n s u r e s s a f e t y . 21 . Food a d d i t i v e s cause c a n c e r . 22. Food a d d i t i v e s a r e n e c e s s a r y i n the modern food s u p p l y . 81 To determine which of the twenty-two statements to include i n the survey, mean scores and standard d e v i a t i o n s were obtained f o r each statement. Three statements were chosen from the high s c o r i n g grouping (pro-food a d d i t i v e s ) and three from the group with the lowest scores ( a n t i - f o o d a d d t i v e s ) . Choice of the s i x statements was based on the high, mid and low mean scores w i t h i n each group and on the standard d e v i a t i o n . 82 (Table V I ) . Table IV - Corresponding P o s i t i v e Statements Statement Average (7-point Score s c a l e ) 15. Food a d d i t i v e s are safe f o r c h i l d r e n . 5. 9 *2 8. Food a d d i t i v e s are harmless. 6. 1 *1 14. Food a d d i t i v e s are r e a l l y only a minor r i s k to 4. 1 h e a l t h . 22. Food a d d i t i v e s are necessary i n the modern food 5. 4 *5 supply. 16. Food a d d i t i v e s mean everyone has enough to eat. 5. 6 *4 5. Food a d d i t i v e s are s e n s a t i o n a l i z e d i n the media. 3. 6 2. Food a d d i t i v e scares are ab s o l u t e nonsense. 4. 6 19. Food a d d i t i v e s are adequately c o n t r o l l e d by food 5. 1 *6 r e g u l a t i o n s . 20. Food a d d i t i v e t e s t i n g ensures s a f e t y . 5. 9 *3 3. Food a d d i t i v e s cannot be l i n k e d to human h e a l t h . 5. 1 *7 4. Food a d d i t i v e e f f e c t s on h e a l t h are extremely 3. 9 s p e c u l a t i v e . *=Rank order of statements based on mean s c o r e s . 83 Table V - Coresponding Negative Statements Statement Average (7-point Score s c a l e ) 11. Food a d d i t i v e s should be avoided. 3. 0 17. Food a d d i t i v e s should be e l i m i n a t e d from food. 1 . 9 *3 9. Food a d d i t i v e s cause d i s e a s e . 2. 5 *6 21 . Food a d d i t i v e s cause cancer. 1 . 4 *1 18. Food a d d i t i v e s are p o t e n t i a l l y hazardous. 2. 6 6. Food a d d i t i v e s are a s e r i o u s r i s k to h e a l t h . 2. 1 *4 13. Food a d d i t i v e s d i s g u i s e i n f e r i o r p r o d u c t s . 2. 6 1 . Food a d d i t i v e s do not improve food q u a l i t y . 3. 3 12. Food a d d i t i v e s are f o r company p r o f i t s o n l y . 1 . 8 *3 10. Food a d d i t i v e use i s out of c o n t r o l . 2. 4 *5 7. Food a d d i t i v e t e s t i n g i s inadequate. 3. 0 *=Rank order of statements based on mean s c o r e s . 84 Table VI - Ranking of Statements as P o s i t i v e or Negative T o t a l P o s i t i v e Statements Score Average Score Std. Dev. 8. Food a d d i t i v e s are harmless. 46 6.1 1 .4 15. Food a d d i t i v e s are safe f o r small 47 5.9 0.83 c h i l d r e n . 16. Food a d d i t i v e s mean everyone has 45 5.6 1 .1 enough to e a t . 9. Food a d d i t i v e s are adequately con- 41 5.1 1 .3 t r o l l e d by Food R e g u l a t i o n s . 20. Food a d d i t i v e t e s t i n g ensures s a f e t y . 47 5.9 1 .1 22. Food a d d i t i v e s are necessary i n the 43 5.4 0.75 modern food supply. Neqative Statements 13. Food a d d i t i v e s d i s g u i s e i n f e r i o r 21 2.6 1 .2 products. 18. Food a d d i t i v e s are p o t e n t i a l l y 1 9 2.6 1.4 hazardous. 10. Food a d d i t i v e use i s out of c o n t r o l . 19 2.4 1 .8 6. Food a d d i t i v e s are a s e r i o u s r i s k to 17 2.1 1 .6 h e a l t h . 17. Food a d d i t i v e s should be e l i m i n a t e d 15 1.9 0.99 from food. • 12. Food a d d i t i v e s are used f o r company 1 4 1 .8 0.89 p r o f i t s o n l y . 21 . Food a d d i t i v e s cause cancer. 1 1 1 .4 0.52 From Tables IV and V, the statements that were the most p o l a r i z e d i n t o p o s i t i v e s and ne g a t i v e s were l i s t e d i n Table VI. From t h i s reduced l i s t of t h i r t e e n statements, the top and bottom of each group was chosen, i . e . , the lowest and hig h e s t s c o r e s . In the negative group, Statement 6 had a score c l o s e to the average f o r that group, and so was chosen as the t h i r d statement. In the p o s i t i v e group, Statement 16 was the c l o s e s t to the average, but, the standard d e v i a t i o n was l e s s i n statement 22., (0.75 vs. 1.1), and , the phr a s i n g i n Statement 16, "Food a d d i t i v e s mean " was not a d i r e c t a s s e r t i o n 85 on the o b j e c t , while Statement 22 was a c l e a r e r a s s e r t i o n : "Food a d d i t i v e s are necessary.". In a d d i t i o n , i t was d e s i r e a b l e f o r completeness, to have corres p o n d i n g and opposing statements i n order to cover the t o t a l range of p o s s i b l e sentiments r e g a r d i n g food a d d i t i v e s . The f o l l o w i n g statements meet t h i s requirement: 21 vs. 8; 19 vs. 6; an 13 vs. 22. Th e r e f o r e , Statement 22 was chosen over Statement 16. These statements a l s o cover a range of extremes, f a l l i n g i n t o the f o l l o w i n g c a t e g o r i e s r e s p e c t i v e l y : 21. Food a d d i t i v e s cause cancer. 8. Food a d d i t i v e s are harmless. 6. Food a d d i t i v e s are a s e r i o u s r i s k to h e a l t h . 19. Food a d i t i v e s are adequately c o n t r o l l e d . 22. Food a d d i t i v e s are necessary i n modern food. 13. Food a d d i t i v e s d i s g u i s e i n f e r i o r p roducts. The statements were r a t e d as such i n the presurvey. These s i x statements were used i n the measure. I I I . THE MAIN SURVEY The main survey (Appendix C) c o n s i s t e d of a number of s e c t i o n s as d e s c r i b e d below. a. General D i r e c t i o n s The g e n e r a l d i r e c t i o n s were g i v e n , s t a t i n g the purpose of the survey, the use of the r e s u l t s , the time a l o t t e d , and the three parts, of the survey. A l s o that completion was v o l u n t a r y , that r e f u s a l to p a r t i c i p a t e would i n no way a f f e c t c l a s s 86 standing and that completion of the survey would be taken as consent. b. Part J_ 2 Your Opinion i . D i r e c t i o n s and Example Respondents were i n s t r u c t e d to i n d i c a t e t h e i r f e e l i n g s about the statement by p l a c i n g an "X" on one of the seven spaces that separated each a d j e c t i v e p a i r , a c c o r d i n g to how c l o s e l y r e l a t e d t h e i r f e e l i n g s were to that word, i i . The Measure In t h i s s e c t i o n , the a t t r i b u t e v a r i a b l e : a t t i t u d e toward food a d d i t i v e s , as w e l l as the c o v a r i a t e : b e l i e f i n food a d d i t i v e statements, were measured. F i s h b e i n ' s a t t i t u d e / b e l i e f measure was used, with each concept measured by four b i p o l a r a d j e c t i v e p a i r s ( F i s h b e i n & Raven, 1967). A t t i t u d e was measured by ' w i s e - f o o l i s h ; good-bad; s i c k - h e a l t h y ; and harmful-b e n e f i c i a l ' . B e l i e f was measured by ' l i k e l y - u n l i k e l y ; improbable-probable; t r u e - f a l s e and p o s s i b l e - i m p o s s i b l e ' . Each a d j e c t i v e p a i r was separated by seven spaces. The respondent i n d i c a t e d which of the spaces most c l o s e l y r e presented h i s or her sentiments r e g a r d i n g the statements, i i i . S c o r i n g the Measure I n d i v i d u a l scores were obtained f o r a respondent's a t t i t u d e ( a t t r i b u t e v a r i a b l e ) and b e l i e f i n the statements ( c o v a r i a t e ) . The b e l i e f / a t t i t u d e measure c o n s i s t e d of e i g h t p a i r s of a d j e c t i v e s ; four measuring b e l i e f and four measuring a t t i t u d e 87 ( F i s h b e i n and Raven, 1967). For the b e l i e f measure, the followng four a d j e c t i v e p a i r s used were arranged i n the f o l l o w i n g manner: Ex. Food a d d i t i v e s are necessary. l i k e l y 7 6 5 4 3 2 J_ u n l i k e l y improbable 7 6 5 4 3 2 _[ probable p o s s i b l e 7 6 5 4_ 3 2 J_ impossible t r u e 7 6 5 4 3 2 J_ f a l s e A high score i n d i c a t e s a s t r o n g b e l i e f and a low score, a weak b e l i e f . There are seven spaces between the a d j e c t i v e p a i r s , and the respondent was asked to mark the space that most c l o s e l y reperesented h i s / h e r a s s o c i a t i o n with the statement. The s c o r i n g i n d i c a t e d i s f o r both p o s t i v e and negative statements. For the a t t i t u d e measure, another set of four a d j e c t i v e p a i r s that were designed to tap the a t t i t u d e domain were used. Again there are seven spaces between the a d j e c t i v e p a i r s and the respondent was asked to i n d i c a t e which space most c l o s e l y corresponded to h i s / h e r sentiments r e g a r d i n g the statement. A high score i n d i c a t e s a p o s i t i v e a t t i t u d e and a low score a negative a t t i t u d e . S c o r i n g i s reversed f o r the p o s i t i v e and negative statements. The a d j e c t i v e p a i r s and scores f o r responses to the p o s i t i v e statements are as f o l l o w s : 88 Ex. Food a d d i t i v e s a re h a r m l e s s , good 7 6 5 4 2 2 1 bad wise 7 § 5 4 3 2 ! f o o l i s h b e n e f i c i a l 7 6 5 4 3 2 j _ h a r m f u l h e a l t h y 7 6 5 4 3 2 1 s i c k T h e r e f o r e , a per s o n who i s a n t i - f o o d a d d i t i v e s , w i l l have n e g a t i v e s e n t i m e n t s about t h i s p o s i t i v e statement and s h o u l d t h e o r e t i c a l l y mark the u n f a v o u r a b l e end of the s c a l e and thus r e c e i v e a low s c o r e . On the o t h e r hand, a pers o n who i s i n f a v o u r of f o o d a d d i t i v e s t h e o r e t i c a l l y w i l l have f a v o u r a b l e s e n t i m e n t s about the statement and thus i n d i c a t e the f a v o u r a b l e end of the s c a l e and o b t a i n a h i g h s c o r e . For the a n t i - f o o d a d d i t i v e s t a t e m e n t s , the response and t h e r e f o r e the s c o r i n g i s r e v e r s e d , as shown i n the f o l l o w i n g example: Ex. Food a d d i t i v e s cause c a n c e r . good 1 2 3 4 5 6 7 bad wise 1 2 3 4 5 6 7 f o o l i s h b e n e f i c i a l 1 2 3 4 5 6 7 h a r m f u l 8 9 h e a l t h y 1 2 3 4 5 6 7 s i c k The respondent who i s f a v o u r a b l e toward food a d d i t i v e s w i l l be unfavourable toward the sentiments expressed i n the statement, and w i l l i n d i c a t e the unfavourable end of the s c a l e , which now r e c e i v e s the h i g h score, and the pro-food a d d i t i v e a t t i t u d e o b t a i n s the high s c o r e . Conversely, f o r the person who i s a n t i - f o o d a d d i t i v e s , the statement t h e o r e t i c a l l y expresses sentiments toward which he/she i s f a v o u r a b l e . Thus the response w i l l be at the f a v o u r a b l e end of the s c a l e , which i s now awarded the low s c o r e , and the a n t i food a d d i t i v e respondent w i l l r e c e i v e a low s c o r e . i v . R e l i a b l i t y T e s t i n g of the Instrument The a t t i t u d e and b e l i e f measures were t e s t e d f o r r e l i a b i l i t y u s i ng The Hoyt R e l i a b i l i t y C o e f f i c i e n t and standard e r r o r of measurement. C o r r e l a t i o n s between the four a d j e c t i v e p a i r s (items) and a) the statements (subtest) and b) a l l s i x statements ( t o t a l t e s t ) were obtained. C o r r e l a t i o n s between each of the statements and the o v e r a l l t e s t were a l s o o b t a i n e d . A n a l y s i s of v a r i a n c e (ANOVA) was conducted on the responses to each statement and f o r the t o t a l t e s t of a l l s i x statements. Table VII summarizes the v a r i o u s forms of the instrument that were t e s t e d . The o r i g i n a l instrument (1a & 1b) was found to be u n r e l i a b l e on the b e l i e f measure ( i e . Hoyt < . 7 4 ) . T h e r e f o r e , v a r i o u s combinations of statements and items were analyzed to o b t a i n the most r e l i a b l e t e s t instrument. D e t a i l e d r e s u l t s of 90 the r e l i a b i l i t y t e s t i n g are i n Appendix D. From the r e l i a b i l i t y a n a l y s i s , i t was concluded that the use of an instrument c o n s i s t i n g of p o s i t i v e statements only was the most r e l i a b l e and a l s o accounted f o r a reasonable amount of v a r i a n c e i n the dependant v a r i a b l e . A l l f u r t h e r a n a l y s e s were based on the use of t h i s instrument c o n s i s t i n g of the p o s i t i v e statements o n l y . Table VII - Summary of Analyses of Instrument R e l i a b i l i t y TEST # TEST DESCRIPTION 1.a A t t i t u d e ( t o t a l t e s t , anti-& pro-statements) RESULT HOYT MSI 0.87 113.69 1. b B e l i e f ( t o t a l t e s t , anti-& pro-statements) 0.58 138.32 2. a ) i A t t i t u d e (anti-& pro-statements) (minus item 1 on a n t i ) 0.85 125.33 a ) i i B e l i e f (anti-& pro-statements) (minus item 4 on pro) 0.46 140.96 3. a) Pro-Statments Only i A t t i t u d e 0.90 64.81 i i B e l i e f 0.88 62.18 b) Anti-Statements Only i A t t i t u d e 0.83 48.49 i i B e l i e f 0.63 202.79 4. a) Pro-Statements Only i B e l i e f (minus item 4) 0.85 45.23 b) Anti-Statements Only i A t t i t u d e (minus it e m l ) 0.86 8.62 5. (Minus 9 surveys with b e l i e f score <4) a) i B e l i e f (n=116) 0.86 8.18 b) i A t t i t u d e (n=H6) 0.84 48.05 i i A t t i t u d e (n=H6, minus item 1 ) 0.86 8.73 6. The dependant v a r i a b l e , B e l i e f i n Pro-92 Food A d d i t i v e Message. 0.96 5.59 7. Due to poor C o e f f i c i e n t of Determination f o r a n t i -statement instrument, the pro-statement instrument was t e s t e d . Pro-statements: a ) i B e l i e f (n=1l6) 0 . 9 0 61 .09 i i B e l i e f (n=116, minus item4) 0 . 8 6 1 .92 b ) i A t t i t u d e (n=116) 0.87 59.16 c. Part 2 The Message The message, w r i t t e n by the r e s e a r c h e r , expressed pro-food a d d i t i v e sentiments. The arguments were expressed f o r c e f u l l y i n order to encourage a source e f f e c t (Hass, 1981). The message was meant to t y p i f y an attempt to counte r a c t m i s i n f o r m a t i o n r e g a r d i n g food a d d i t i v e s . The message s t a r t e d out by r a i s i n g o p p o s i t i o n viewpoints, such as the p u b l i c i s u n c e r t a i n about food; that l a b e l s r e q u i r e a degree i n chemistry to be understood; and names of a d d i t i v e s are d i f f i c u l t to pronounce. Next came the main p o i n t or c o n c l u s i o n of the message: that the r i s k to h e a l t h from food a d d i t i v e s has been g r e a t l y exaggerated. Arguments used to support t h i s p o i n t i n c l u d e d quotes by exp e r t s r e g a r d i n g cancer s t a t i s t i c s ; the b e n e f i t s of food a d d i t i v e s ; t h a t concerns have been e x p l o i t e d by the media; that a d d i t i v e s are adequately c o n t r o l l e d ; t h a t " a l l n a t u r a l " may be a sham; and the reason f o r worry i s due to a lack of common sense. 93 The message was typeset to appear as though i t were a c l i p p i n g from a newspaper or magazine. The source of the message i e , the author, was p r i n t e d a f t e r the l a s t l i n e of the a r t i c l e . In b r a c k e t s below t h i s , an e d i t o r ' s note i d e n t i f i e d the source as a food s c i e n t i s t , or n u t r i t i o n i s t or medical doctor or, i n the case of the c o n t r o l , no e d i t o r ' s note appeared. d. Par t 3 Your Reaction to the Message v. D i r e c t i o n s and Example Respondents were asked to i n d i c a t e t h e i r r e a c t i o n to the i n f o r m a t i o n i n the message, keeping i n mind the source of the message. F u r t h e r d i r e c t i o n s were s i m i l a r to those d e s c r i b e d i n 2 ( a ) . An a c t u a l sample of a b i p o l a r a d j e c t i v e p a i r , separated by 7 spaces was given-. Respondents were asked to i n d i c a t e how c l o s e l y r e l a t e d the chosen a d j e c t i v e was to t h e i r r e a c t i o n , by the l o c a t i o n of the "X" on one of the 7 spaces. v i . The Measure At the top of the page, the f o l l o w i n g d i r e c t i o n s were g i v e n : "Please keep i n mind the WRITER of the message, as i d e n t i f i e d at the end of the a r t i c l e . What i s your r e a c t i o n to the i n f o r m a t i o n i n the message? Place an "X" i n the a p p r o p r i a t e space f o r each a d j e c t i v e p a i r . " T h i s was f o l l o w e d by the four a d j e c t i v e p a i r s that measure b e l i e f , p l u s a f i f t h p a i r , t r u e - f a l s e . T h i s l a t t e r p a i r was not used in the a n a l y s i s . 94 The f r e q u e n c y of responses f o r each of the 7 p o s s i b l e c a t e g o r i e s f o r the b e l i e f i n the statement measure; f o r the a t t i t u d e measure and f o r the b e l i e f measure were o b t a i n e d , t a b u l a t e d and d i s p l a y e d i n h i s t o g r a m s . These r e s u l t s were used i n an attempt t o e x p l a i n the r e s u l t s of the g r a p h i n g of r e g r e s s i o n p l a n e s g i v e n i n F i g u r e 2, Chapter 4. M u t l i p l e r e g r e s s i o n a n a l y s i s was con d u c t e d and p a r t i a l r e g r e s s i o n c o e f f e c i e n t s g e n e r a t e d f o r each v a r i a b l e , u s i n g the BMD:03R computer programme. An ANOVA was run on the mean s c o r e s of the v a r i a b l e s . The r e s u l t s of m u l t i p l e r e g r e s s i o n a n a l y s i s were a n a l y s e d f o l l o w i n g Pedhazur's (1982) s i x s t e p s , and the r e g r e s s i o n p l a n e s were graphed. IV. ANALYSIS OF THE RESULTS I . DESIGN In t h i s d e s i g n , an ATTRIBUTE FACTOR, a t t i t u d e toward food a d d i t i v e s , was a c o n t i n u o u s v a r i a b l e . S u b j e c t s were randomly a s s i g n e d t o TREATMENT GROUPS t h a t r e c e i v e d a common message about food a d d i t i v e s from d i f f e r e n t s o u r c e s . I t i s r e a s o n a b l e t o expect t h a t b e l i e f s c o r e s i n response t o a food a d d i t i v e message w i l l v a r y a c r o s s l e v e l s of a t t i t u d e (degree of f a v o u r a b l e n e s s / u n f a v o u r a b l e n e s s ) toward f o o d a d d i t i v e s ( M c G i n n i e s , 1973; Hass, 1981; McCrosky, 1978). S i n c e s u b j e c t s r e p r e s e n t i n g d i f f e r e n t l e v e l s of f a v o u r a b l e n e s s toward f o o d a d d i t i v e s may a l s o d i f f e r i n t h e i r b e l i e f s about s t a t e m e n t s made about fo o d a d d i t i v e s , a n o t h e r v a r i a b l e , c a l l e d t he COVARIATE, which i s b e l i e f s about fo o d a d d i t i v e s t a t e m e n t s , i s 95 i n c l u d e d . T h i s v a r i a b l e a l l o w s f o r d i f f e r e n c e s due t o b e l i e f s t r e n g t h and p e r m i t s a more p o w e r f u l t e s t f o r t h e i n t e r a c t i o n between food a d d i t i v e a t t i t u d e and t h e source of a food a d d i t i v e message by r e d u c i n g the r e s i d u a l e r r o r (Delaney and M a x w e l l , 1981). I I . THE MODEL The d e s i g n of t h i s s t u d y f o l l o w s a s p e c i a l c a s e of m u l t i p l e r e g r e s s i o n u s i n g an a t t r i b u t e by t r e a t m e n t i n t e r a c t i o n (ATI) model (Delaney and M a x w e l l , 1981). The f o l l o w i n g i s the model on which t h i s d e s i g n i s based: Y i j = An + A l X i j I +02Xij2 +03Xij3 +p>4Xij4 +£5Xij5 +p6Xij6 + 0 7 X i j 7 +(&8Xij8 +eij Where: i = 1 , 2 , N j = 1,2,3 ( t r e a t m e n t l e v e l , i . e . souce of message) Y i j = The DEPENDENT VARIABLE b e l i e f i n the message /50 = A CONSTANT £ 1 - 0 8 = P a r t i a l r e g r e s s i o n w e i g h t s of v a r i a b l e s X1 t o X8 X1, X2, X3 = EFFECT CODING VECTORS d e n o t i n g which SOURCE the s u b j e c t s r e c e i v e d . X4 = the COVARIATE, b e l i e f i n f o o d a d d i t i v e statement X5 = the ATTRIBUTE, a t t i t u d e towards food a d d i t i v e s X6 = the INTERACTION between X1 and X5 X7 = the INTERACTION between X2 and X5 X8 = the INTERACTION between X3 and X5 € . i j . = RESIDUAL e r r o r 9 6 i . E f f e c t Coding of Treatment V a r i a b l e s E f f e c t coding i s t y p i c a l l y used i n f a c t o r i a l designs i n which treatment groups are l i k e l y to be of unequal s i z e and i n t e r a c t i o n s are l i k e l y to be s i g n i f i c a n t . E f f e c t coding leads to p a r t i a l r e g r e s s i o n weights f o r treatment v a r i a b l e s which are e q u i v a l e n t to treatment e f f e c t s i n an ANOVA. Although there were only three v e c t o r s used to i d e n t i f y the treatments, a l l four sources were accounted f o r , and were coded as can be seen below: X1 SOURCE 1 1 SOURCE 2 0 SOURCE 3 0 SOURCE 4 -1 T h i s v e c t o r coding i s c a l l e d e f f e c t v e c t o r coding, and i s r e q u i r e d by the design of the r e s e a r c h . In m u l t i p l e r e g r e s s i o n a n a l y s i s i n v o l v i n g treatment, the number of treatment v e c t o r s used i s always one l e s s than the the number of treatment groups. The f o u r t h treatment group i s i d e n t i f i e d i n terms of the way the three treatment v e c t o r s are coded ( K e r l i n g e r and Pedhazur, 1973). V. STATISTICAL HYPOTHESES S t a t i s t i c a l Hypothesis #1 To t e s t the r e g r e s s i o n model to determine i f a s t a t i s t i a l l y s i g n i f i c a n t amount of v a r i a n c e i s accounted f o r , the f o l l o w i n g n u l l h y p o t h e s i s was X2 X3 0 0 1 0 0 1 -1 -1 97 t e s t e d s t a t i s t i c a l l y at the a=.05 l e v e l of s i g n i f i c a n c e : HO: B1=£>2=03=|04 = A5=£6=p7=p8 = O (none of the v a r i a b l e s account f o r s i g n i f i c a n t v a r i a n c e ) H1: Not a l l p's equal 0 (some of the v a r i a b l e s i n the equation account f o r a s i g n i f i c a n t amount of v a r i a n c e ) S t a t i s t i c a l Hypothesis #2 To t e s t Research Hypotheses #3, the f o l l o w i n g n u l l h y p o t hesis was t e s t e d s t a t i s t i c a l l y at the a=.lO l e v e l of s i g n i f i c a n c e : HO: g>6 = pi = £ 8 = 0 ( i . e . there are no s i g n i f -i c a n t i n t e r a c t i o n e f f e c t s ) H1: ft6,pi,p8 are not a l l equal to 0 S t a t i s t i c a l Hypothesis #3 To t e s t Research Hypothesis #1, the f o l l o w i n g n u l l h y pothesis would be t e s t e d s t a t i s t i c a l l y at the <>c=.05 l e v e l of s i g n i f i c a n c e i f there were no s i g n i f i c a n t i n t e r a c t i o n e f f e c t s : HO: (b 1 =j&2=/*3 = 0, ( i e . , no s i g n i f i c a n t e f f e c t s due to source of the message) H1: not a l l A's are equal to 0. 98 S t a t i s t i c a l Hypothesis #4 To t e s t Research Hypothesis #2, the n u l l h y p o t h e s i s would be t e s t e d s t a t i s t i c a l l y at the<* = .05 l e v e l of s i g n i f i c a n c e , i f there were no i n t e r a c t i o n e f f e c t s : HO: ^5=0 ( i . e . , no s i g n i f i c a n t e f f e c t s due to r e c e i v e r a t t i t u d e s toward food a d d t i v e s ) H1: p5 i s not equal to 0 These s t a t i s t i c a l hypotheses were t e s t e d u s i n g m u l t i p l e r e g r e s s i o n a n a l y s i s and are r e p o r t e d i n the f o l l o w i n g chapter. 99 IV. RESULTS I . MULTIPLE REGRESSION ANALYSIS A l i n e a r m u l t i p l e r e g r e s s i o n a n a l y s i s was co n d u c t e d on the v a l u e s of v a r i a b l e s i n the r e g r e s s i o n e q u a t i o n . The model of the r e g r e s s i o n e q u a t i o n i s r e p e a t e d here f o r the c o n v e n i e n c e of the r e a d e r : Y i j = £0 + j f t l X i j I + ^ 2 X i j 2 + (93Xij3 + £>4Xij4 + /2>5Xij5 + /36Xij6 + £ 7 X ^ 7 + £8Xij8 + 6 i j Computer a n l a y s i s u s i n g the BMD:03R programme, g e n e r a t e d a c o r r e l a t i o n m a t r i x , C o e f f i c i e n t of D e t e r m i n a t i o n , the p a r t i a l r e g r e s s i o n w i e g h t s f o r each of t e v a r i a b l e s i n the model, and an ANOVA t a b l e ( a n a l y s i s of v a r i a n c e , i n c l u d i n g F - v a l u e ) . The c o r r e l a t i o n m a t r i x shows the degree t o whi c h v a r i a b l e s a r e c o r r e l a t e d w i t h each o t h e r , i . e . , how much they o v e r l a p . I f v a r i a b l e s a r e t r u l y independent, the c o r r e l a t i o n s h o u l d be l e s s t han 0.50. I f v a r i a b l e s a r e c o r r e l a t e d , i . e . , measure the same t h i n g , the c o r r e l a t i o n c o e f f i c i e n t w i l l be c l o s e t o 1.00. 100 T a b l e V I I I -C o r r e l a t i o n M a t r i x of V a r i a b l e s i n the R e g r e s s i o n E q u a t i o n 1 2 3 4 5 6 7 8 Y 1 1.00 0.49 0.49 -0.16 0.02 0.94 0.47 0.43 0.04 2 - 1.00 0.48 - 0 . 1 7 - 0 . 0 2 0.46 0.95 0.43 0.04 3 - 1.00 -0.01 0.16 0.46 0.46 0.96 -0.02 4 - - - 1.00 0.73 -0.16 -0.19 -0.02 0.63 5 - - 1.00 0.03 -0.04 0.13 0.57 6 - - - 1.00 0.49 0.46 -0.01 7 - - - - 1.00 0.46 0.07 8 - _ _ _ _ - _ 1.00 -0.04 Y - _ _ _ - - 1 .00 ( V a r i a b l e s 1,2- and 3=Treatment Codes; 4 = C o v a r i a t e ; 5 = A t t r i b u t e ; 6,7 and 8 = I n t e r a c t i o n V a r i a b l e s ; and Y=Dependent V a r i a b l e . ) In T a b l e V I I I , i t can be seen t h a t X4, the c o v a r i a t e ( b e l i e f i n the s t a t e m e n t s ) and the a t t r i b u t e v a r i a b l e , X5 ( a t t i t u d e toward fo o d a d d i t i v e s ) have a c o r r e l a t i o n c o e f f i c e n t of 0.73, which i s q u i t e h i g h . When two v a r i a b l e s t h a t a r e meant t o be independent a r e found t o be c o r r e l a t e d , t h e r e a r i s e s the p o s s s i b l i t y of m u l t i c o l l i n i a r i t y . M u l t i c o l l i n i a r i t y i s a problem which l e a d s t o the c a l c u l a t e d F v a l u e b e i n g u n d e r e s t i m a t e d , and doubts a r e c a s t upon the v a l i d i t y of the s t a t i s t i c a l a n a l y s i s (Wonnacut and Wonnacut, 1978). In o r d e r t o t e s t whether or not m u l t i c o l l i n i a r i t y i s the problem h e r e , Lewis-Beck (1980) recommends t h a t each independent v a r i a b l e be 101 reg r e s s e d on a l l the other independent v a r i a b l e s i n the equa t i o n . When any form of the c o e f f i c i e n t of de t e r m i n a t i o n from these equations i s near 1, m u l t i c o l l i n e a r i t y i s h i g h l y probable. Table IX - Test For M u l t i c o l l i n e a r i t y Regression of Independent V a r i a b l e j on the Remaining Seven Independent V a r i a b l e s C o e f f i c i e n t F u l l Model of Determination Reduced Model X1 on remaining 7 v a r i a b l e s 0.90 0.34 (R a1.2345678) X2 on remaining 7 v a r i a b l e s 0.90 0.34 (R*2.1345678) X3 on remaining 7 v a r i a b l e s 0.91 0.36 (R*3.1245678) . X4 on remaining 7 v a r i a b l e s 0.21 0.19 (R x4.1235678) X5 on remaining 7 v a r i a b l e s 0.24 0.19 (R x5.1234678) X6 OX1X5) on remaining " 0.88 -(R*6. 1 234578) X6 (=X2X5) on remaining " 0.89 -(R x7.1234568) X8 (=X3X5) on remaining " 0.90 — (R 2^. 1234567) From Table IX, i t can be seen that the C o e f f i c i e n t s of Determination f o r the F u l l Model (no v a r i a b l e s removed) are c l o s e to a value of 1.00 f o r X1, X2, X3, X6, X7, and X8. T h i s makes sense as the 6,7 and 8 are the ATI terms and c o n s i s t of the product of the treatment terms (X1, X2 and X3) and the a t t r i b u t e term (X5). When the i n t e r a c t i o n terms, X6, X7 and X8 are removed, as shown i n Table IX under Reduced Model, none of the C o e f f i c i e n t s of Determination are c l o s e t o a value of 1.00. Thus, with the reduced model there i s no problem wth m u l t i c o l l i n i a r i t y . I t i s not a s e r i o u s enough problem to abandon the whole model. I t i s i n t e r e s t i n g to note that the 102 a t t r i b u t e and c o v a r i a t e are not c o l l i n e a r , as was f i r s t thought from the c o r r e l a t i o n matrix (0.72). Thus, when the f u l l model i s used, i t must be remembered that any F value c a l c u l a t e d w i l l be underestimated (Lewis-Beck, 1980). Table X - ANOVA For the F u l l Model R* Y. 1 2345678 = 49. 23% BO = 0.53 Source of Va r i a n c e Degrees of Sums of Mean Squares F Value Freedom Squares Due to Regression 8 167 .84 20. 98 14.06 D e v i a t i o n about Regression 116 173 .12 1 . 49 T o t a l 1 24 340 .96 103 Table XI - M u l t i p l e Regression A n a l y s i s - F u l l Model Esti m a t e s of the Model V a r i a b l e P a r t i a l R e gression P r o p o r t i o n of C o e f f i c i e n t V a r i a n c e Increment X1 1.5770 0.00 X2 0.1801 0.00 X3 -0.8246 0.00 X4 0.7071 0.44* X5 0.3375 0.02 X6 -0.3481 0.02 X7 0.0514 0.02 X8 0.1032 0.00 * 44% of the v a r i a n c e i n Y was accounted f o r by X4 I I . THE SIX STEPS IN THE ANALYSIS The f o l l o w i n g a n a l y s i s f o l l o w s the recommended s i x steps i n a n a l y s i s of m u l t i p l e r e g r e s s i o n (Pedhazur, 1982). S t e p l . a ) Is the p o r p o r t i o n of v a r i a n c e accounted f o r by the f u l l model s i g n i f i c a n t ? 2 R Y.12345678 = 49.23% T h i s i n d i c a t e s that the v a r i a b l e s i n the r e g r e s s i o n equation, i . e . , the a t t i t u d e measure; the c o v a r i a t e , b e l i e f i n the statements; and the treatments, sources, account f o r almost 50 % of the v a r i a n c e i n b e l i e f i n the pro-food a d d i t i v e message. T h i s amount seems reasonable when compared to the 51% that 104 Wheeless (1978) was a b l e t o a c c o u n t f o r i n h i s s t u d y which i n v o l v e d a s i m i l a r model. I n a d d i t i o n , i n terms of the v a r i a b l e s t h a t a r e known t o a f f e c t b e l i e f i n a message, such as message s t y l e , arguments, the appearance of the message, the o t h e r s o u r c e f a c t o r s and numerous a u d i e n c e v a r i a b l e s which were not i n c l u d e d as v a r i a b l e s , the 49.23% v a r i a n c e o b t a i n e d i s q u i t e s a t i s f a c t o r y . S t e p 1.b) I s the o v e r a l l r e g r e s s i o n e q u a t i o n s i g n i f i c a n t ? I . STATISTICAL HYPOTHESIS £1_ HO: <31=/32=(&3=|B4=^5=p6=B7=B8 = 0 H1 : not a l l (&'s = 0 From ANOVA,Table X I I I : F ( c a l c u l a t e d ) = 14.0584 The t a b l e d v a l u e of F: .95 F (8,116) = 2.02 S i n c e the c a l c u l a t e d F i s g r e a t e r than the t a b l e d v a l u e , r e j e c t Ho: t h a t a l l v a r i a b l e s do not account f o r a s i g n i f i c a n t amount of v a r i a n c e . Some of t h e v a r i a b l e s t h e r e f o r e do account f o r a s i g n i f i c a n t amount of v a r i a n c e i n b e l i e f i n the message. St e p 2 . I s t h e r e any s i g n i f i c a n t i n t e r a c t i o n ? I I . STATISTICAL HYPOTHESIS #2 HO: £ 6 = (3 7 = 3^8 = 0 H1 : not a l l A ' s = 0 F = (R^Y.12345789 - R Y.12345) / k1-k2 (1-R2Y12345789) / n-K1-1 (0.4923 - 0.4672) / 8-5 = 1.91 (1-0.4923) / 125-8-1 105 The t a b l e d value of .90 F 8,116 =1.72 Since the c a l c u l a t e d F value i s g r e a t e r than the t a b l e d v a l u e , we r e j e c t HO, and t h u s , i t i s tenable that there are s i g n i f i c a n t i n t e r a c t i o n e f f e c t s . That i s , the sources and the respondent's a t t i t u d e s i n t e r a c t together to i n f l u e n c e the amount of b e l i e f i n a pro-food a d d i t i v e message. Because of t h i s i n t e r a c t i o n , i t now becomes i n a p p r o p r i a t e to look at the remaining s t a t i s t i c a l hypotheses, #3 and #4. That there i s an i n t e r a c t i o n between the source of the message and the a t t i t u d e of the respondent p r e c l u d e s any unique e f f e c t by the sources alone, or by a t t i t u d e a l o n e . T h e r e f o r e , steps 3,4 and 5 were not c a r r i e d out, and the a n a l y s i s proceeded to Step 6 i n Pedhazur (1982). Step 6. P l o t t i n g the Treatment Regression Planes The o v e r a l l estimated r e g r e s s i o n equation i s : A Y i j = 0.5186 + 1.577Xij1 +0.l801Xij2 + (-0.8246)Xij3 + 0.7071Xij4 + 0.3375Xij5 + (-0.3481)Xij6 + 0 . 5 l 4 3 X i j + 0.l032Xij8 Where the b-estimates ( p a r t i a l r e g r e s s i o n c o e f f i c i e n t s ) are given i n Table X I I I . The i n d i v i d u a l treatment r e g r e s s i o n planes were obtained as f o l l o w s : Example 1. Treatment 1, N u t r i t i o n s i t In t h i s case, the f o l l o w i n g v a r i a b l e s i n Equation have the v a l u e s : 106 X1=1 X2=0 X3=0 X6 = X1X5 =X5 X7 = X2X5 = 0 X8 = X3X5 = 0 The treatment plane equation becomes: A Y i j = 2.10886 + 0.707lXij4 - 0.0l06Xij5 T h i s equation was graphed as shown i n F i g u r e 2. In a s i m i l a r way, the treatment equation was obtained and graphed f o r the other teatments. Treatment 2, Food S c i e n t i s t X1=0 X2=1 X3=0 X6 = X1X5=0 X7 = X2X5 =X5 X8 = X3X5 = 0 The treatment plane equation becomes: A Y i j = 0.71196 + 0.7071Xij4 + 0.38893Xij5 Treatment 3, M e d i c a l Doctor X1=0 X2=0 X3=1 X6 = X1X5 = 0 X7 = X2X5 = 0 X8 = X3X5 = X5 The treatment plane equaion becomes: Y i j = -0.29274 + 0.707lXij4 + 0.4407Xij5 Treatment 4, C o n t r o l XI=-1 X2=-1 X3=-1 X6 = X1X5 = (~1)X5 X7 = X2X5 = (~1)X5 X8 = X3X5 = (~1)X5 The treatment plane equation becomes: Y i j = - 0.29274 + 0.7071Xij4 + 0.53!0Xij5 107 These equations were graphed i n a space spanned by three dimensions: a t t i t u d e (X4), and b e l i e f (X5), and b e l i e f i n the message ( ( F i g u r e 2 ) . F i g u r e 2 - Graph of Treatment R e g r e s s i o n P l a n e s 109 As can be seen from F i g u r e 2, t h e r e i s indeed an i n t e r a c t i o n between the t r e a t m e n t v a r i a b l e s ( s o u r c e ) and the a t t r i b u t e v a r i a b l e , a t t i t u d e toward food a d d i t i v e s . The b e l i e f i n the message does not change a p p r e c i a b l y over the range of a t t i t u d e l e v e l s f o r those r e s p o n d e n t s who r e c e i v e d the message from the n u t r i t i o n i s t . As the n u t r i t i o n i s t was r a t e d the most c r e d i b l e , perhaps the c r e d i b i l i t y e f f e c t overcomes the a t t i t u d e e f f e c t . The o t h e r t h r e e s o u r c e s have r e a s o n a b l y s i m i l a r s l o p e s (0.39 f o r Source 2, the Food S c i e n t i s t ; 0.44 f o r Source 3, the M e d i c a l D o c t o r and 0.53 f o r Source 4, the c o n t r o l ) . Because the e f f e c t s of a t t i t u d e a l o n e , the t r e a t m e n t a l o n e and the b e l i e f i n the s t a t e m e n t s a l o n e cannot be i n t e r p r e t e d s t a t i s t i c a l l y , i t i s of i n t e r e s t t o examine the e f f e c t s of the s e v a r i a b l e s t h r o u g h i n t e r p r e t a t i o n of the graph of the r e g r e s s i o n p l a n e s . I I I . RESEARCH HYPOTHESIS#3 Re s e a r c h H y p o t h e s i s #3 c o n s i d e r s the e f f e c t of source a l o n e on b e l i e f i n the message. I t can be seen from t h e graph t h a t t h a t the f o u r s o u r c e s v a r y i n terms of t h e i r e f f e c t on b e l i e f i n the message. I t appears as i f the a n t i - f o o d a d d i t i v e r e s p o n d e n t s ( a t t i t u d e s c o r e < 2.5) tended t o b e l i e v e the message more so i f the sour c e was the n u t r i t i o n i s t . For t h o s e who were undecided i n t h e i r a t t i t u d e s , ( a t t i t u d e s c o r e 3.5-4.5), the o r d e r of s o u r c e e f f e c t i v e n e s s changes, w i t h the f o o d s c i e n t i s t r e s u l t i n g i n s l i g h t l y g r e a t e r b e l i e f than the n u t r i t i o n i s t , f o l l o w e d by the c o n t r o l , then the m e d i c a l d o c t o r . 110 Just beyond the midscore range, at approximately 4.5, the order again changes, with the food s c i e n t i s t > c o n t r o l > n u t r i t i o n i s t > medical d o c t o r . Again, j u s t a f t e r the score reaches 5, i n d i c a t i v e of more p o s i t i v e a t t i t u d e s toward food a d d i t i v e s , the order changes, with the food s c i e n t i s t r e s u l t i n g i n g r e a t e r b e l i e f i n the message than the c o n t r o l , who was more e f f e c t i v e than the medical doctor and the n u t r i t i o n i s t f a l l s to l a s t p l a c e . It should be noted that although the sources vary i n t h e i r e f f e c t on b e l i e f i n the message, the b e l i e f i n the message score b a r e l y makes 4 on the s c a l e . T h i s i n d i c a t e s that the message was s t i l l not h i g h l y b e l i e v e d by some of the respondents. Indeed, the mean score f o r b e l i e f i n the message was only 4.26 (Table XV). IV. RESEARCH HYPOTHESIS #4 Research Hypothesis #4 c o n s i d e r e d the e f f e c t of a t t i t u d e on b e l i e f i n the message. From F i g u r e II (see page 118), i t appears that as the a t t i t u d e score i n c r e a s e s , so does b e l i e f i n the message. T h i s occurs f o r a l l sources, except the n u t r i t i o n i s t . For the respondents who r e c e i v e d the n u t r i t i o n i s t as the source, b e l i e f i n the message d i d not change a p p r e c i a b l l y over the f u l l range of a t t i t u d e s c o r e s . Because the message i s pro-food a d d i t i v e s , i t makes sense that those with s i m i l a r v i e w p o i n t s , that i s with a t t i t u d e s c o r e s i n d i c a t i n g a p o s i t i v e p r e d i s p o s i t i o n toward food a d d i t i v e s , would have a g r e a t e r b e l i e f i n the message. 111 V. PROPORTION OF VARIANCE INCREMENT From Table X, the P o r p o r t i o n of V a r i a n c e Increment i n d i c a t e s the amount of the o v e r a l l t o t a l v a r i a n c e that i s accounted f o r by each independent v a r i a b l e . I t can be seen that the c o v a r i a t e , b e l i e f i n food a d d i t i v e statements,accounts f o r the m a j o r i t y of the accountable v a r i a n c e : i e . , 44.14% out of 49.23%, which i s about 89%. A c t u a l l y , t h i s term ( p r o p o r t i o n of v a r i a n c e increment) means the amount of v a r i a n c e a p a r t i c u l a r v a r i a b l e accounts f o r , with a l l the preceeding v a r i a b l e s removed. Thus X2's p o r p o r t i o n of v a r i a n c e increment means the amount of v a r i a n c e acounted f o r by X2, with the amount f o r X1 removed from the e q u a t i o n . I t i s q u i t e reasonable f o r the c o v a r i a t e to account f o r t h i s much v a r i a n c e as the sentiments expressed i n the statements are s i m i l a r to the o v e r a l l setiments i n the message. In a d d i t i o n , the same measurement s c a l e was used f o r the c o v a r i a t e and the dependent v a r i a b l e measure. The a t t r i b u t e v a r i a b l e , a t t i t u d e toward food a d d i t i v e s , accounted f o r only 2.16 % compared to the o v e r a l l 49.23%. T h i s r e s u l t may be due to the measure i t s e l f . For the a t t i t u d e measure to work p r o p e r l y , the statement on which the response i s based must be b e l i e v a b l e ( F i s h b e i n and Raven, 1967). From Table XII, and F i g u r e 3, i t can be seen that 50.4% of respondents d i d not b e l i e v e the statements, i e . score < 3.5. When the a s s e r t i o n beween the s u b j e c t and the o b j e c t i s not b e l i e v a b l e , the response i s not based on the sentiments f e l t about the statement. Instead, the response i s focused on the sub j e c t of the statement alone. 1 12 T h i s does not s e r i o u s l y a f f e c t s c o r i n g of the p o s i t i v e statements, as respondents who are a n t i - f o o d a d d i t i v e w i l l s t i l l mark the unfavourable end of the s c a l e and r e c e i v e a, low score, while pro-food a d d i t i v e respondents w i l l mark the favourable end and r e c e i v e a h i g h s c o r e . T h i s would not be the case for responses to the a n t i - f o o d a d d i t i v e statements (See Appendix E, V I ) . Another reason may be due to the overwhelming m a j o r i t y of respondents, 74.4%, r e c e i v i n g an a t t i t u d e score of l e s s than 4.5, i n d i c a t i n g predominantly negative (<3.5) or undecided (3.51-4.5) a t t i t u d e s (Table X I I I , F i g u r e 4). When most of the reponses on the a t t i t u d e measure are s i m i l a r , i t i s more d i f f i c u l t to e x p l a i n that the b e l i e f i n the message w i l l f l u c t u a t e with a t t i t u d e , s i n c e a t t i t u d e remains f a i r l y constant. Whereas, i f t h e r e was a wide range of a t t i t u d e scores, a f l u c t u a t i o n i n scores may c o r r e l a t e with d i f f e r e n t l e v e l s of b e l i e f . I I I . ANCILLARY RESULTS I. FREQUENCY DISTRIBUTION OF SCORES Although not d i r e c t l y p a r t of the r e s e a r c h d e s i g n , i t was f e l t t h a t that some i n f o r m a t i o n about the frequency d i s t r i b u t i o n of the scores would be r e l e v a n t to i n t e r p r e t a t i o n of the m u l t i p l e r e g r e s s i o n a n a l y s i s . The d i s t r i b u t i o n of mean scores f o r the c o v a r i a t e , b e l i e f i n food a d d i t i v e statements; f o r the a t t t r i b u t e , a t t t i t u d e toward food a d d i t i v e s ; and the dependent v a r i a b l e , b e l i e f i n a p r o - f o o d a d d i t i v e message were t a b u l a t e d 1 13 and the r e s u l t s presented i n histograms. These r e s u l t s have been r e f e r r e d t o p r e v i o u s l y i n the d i s c u s s i o n . Table XII -Mean Scores and Frequency of Response f o r the BELIEF MEASURE Statements #1 #5 #6 Average Score Freq. % Cum.% Freq. % Cum.% Freq . % Cum. % F r e q . % Cum.% 1 12 9 .0 9.6 29 23.2 23.2 14 11.2 11.2 8 6.4 6.4 2 2 21 .6 31.2 22 17.6 40.8 1 1 8.8 20.6 1 5 12.0 18.4 3 30 24 .0 55.2 28 22.4 63.2 10 8.0 28.0 40 32.0 50.4 4 28 22 .4 77.6 28 22.? 85.6 33 26.4 54.4 33 26.4 76.8 5 1 5 1 2 .0 89.6 14 11.2 96.8 31 24.8 79.2 23 18.4 95.2 6 1 2 9 .6 99.2 4-3.2 100 22 17.6 96.8 6 4.8 100 7 1 0 .8 100 - - 4 3.2 100 - - -Mean score 3. 376 2. 904 4. 104 3. 528 1 14 F i g u r e 3 -Histogram of Mean Response Scores f o r BELIEF i n Pro-Statements Code I 1^  j ******** (g) ( 0 .5-1*5 )1 I 2. j * * * * * * * * * * * * * * * ( 1 5 ) (1.51-2.5)1 I 3^  j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (40) ( 2 .51-3*5 )1 I 4^  j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (33) (3.51-4*5)1 I 5 ^ j * * * * * * * * * * * * * * * * * * * * * * * (23) ( 4 .51-5*5 )1 I S, i * * * * * * (6) (5.51-6.5)1 I 7 . 1 (6.51-7.0)1 I I I I I I I 0 10 20 30 40 50 Frequency of Response (Numbers i n br a c k e t s = frequency) As can be seen from Table X I I , the average score f o r b e l i e f i n the pro-food a d d i t i v e statements (the c o v a r i a t e ) was 3.53. T h i s g e n e r a l l a c k of s t r o n g b e l i e f i n the pro-food a d d i t i v e statements was i l l u s t r a t e d i n F i g u r e 3 which showed the standard curve reached i t s maximum l e v e l at a b e l i e f score of 2.51-3.50. 1 15 Table XIII - Response Frequency of Mean ATTITUDE Scores Statements #1 #5 #6 Average Code Freq % Cum.% Freq . % Cum.% Freq . % Cum.% Freq . % Cum. 1 6 4.8 4.8 29 23.2 23.2 1 7 13.6 13.6 7 5 .6 5.6 2 1 5 12.0 16.8 28 22.4 45.6 16 12.8 26.4 16 1 2 .8 18.4 3 23 18.4 35.2 25 20.0 65.5 14 11.2 37.6 30 24 .0 42.4 4 1 6 12.8 48.0 31 24.8 90.4 53 42.4 80.0 40 32 .0 74.4 5 21 16.8 64.8 6 4.8 95.2 18 14.4 94.4 25 20 .0 94.4 6 24 19.2 84.0 4 3.2 98.4 3 2.4 96.8 7 5 .6 100 7 20 16.0 10.0 2 1 .6 100 4 3.2 100 - - -Mean Score 4.464 2. 816 3. 512 2 .648 From Table X I I I , the average mean a t t i t u d e score was 2.65, i n d i c a t i n g an o v e r a l l n e g ative a t t i t u d e toward food a d d i t i v e s . These r e s u l t s support p r e v i o u s surveys that measured a t t i t u d e s toward food a d d i t i v e s (Knox and S c h r e i b e r , 1980; Z i b r i k et a l . , 1981). F i g u r e 4 showed that the responses were mostly on the negative or n e u t r a l p o r t i o n s of the graph. 116 F i g u r e 4 - Histogram of Mean ATTITUDE Scores Code I 1 I ******* ( 7 ) (0.5-1.5) I I 2t j * * * * * * * * * * * * * * * * ( 1 6 ) (1.51-2*5)1 I 3^  j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (30) (2.51-3.5)1 I 4^  j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (40) (3.51-4*5)1 I 5. j * * * * * * * * * * * * * * * * * * * * * * * * * (25) (4.51-5.5)1 I g # I ******* (7 ) (5.51-6.5)1 I 7. I (6.51-7.0)1 I I I I I I 0 10 20 30 40 Frequency of Responses (Number i n brackets = frequency) .1 50 117 Table XIV -Response Frequency of Mean MESSAGE BELIEF Scores Code Fre q . % Cum.% 1 1 2 9.6 9.6 2 12 9.6 19.2 3 13 10.4 29.6 4 21 16.8 46.4 5 35 28.0 74.4 6 26 20.8 95.2 7 6 4.8 100 Mean Score 4.256 From Table XIV, the mean score f o r b e l i e f i n the pro-food a d d i t i v e message was 4.26, i n d i c a t i n g t h at o v e r a l l , b e l i e f i n the message was undecided, or weak. A c l o s e r examination of the scores i n F i g u r e 5, shows that q u i t e a l a r g e p o r t i o n of respondents scored i n the p o s i t i v e b e l i e f range (4.51-7.0). From Table XIV, these respondents represent 53.6% of a l l respondents. 118 F i g u r e 5 - Histogram of Mean BELIEF i n MESSAGE Scores Code I y t I ************ (12) (0.5-1!5)I I 2. j * * * * * * * * * * * * (12) (1.51-2.5)1 I 3^  j * * * * * * * * * * * * * (13) (2.51-3.5)1 I 4^ j * * * * * * * * * * * * * * * * * * * * * (21) (3.51-4.5)1 I 5. j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (35) (4.51-5.5)1 I 6^  j * * * * * * * * * * * * * * * * * * * * * * * * * * (26) (5.51-6!5)I I 7 1 ! * * * * * * (g) I I I I I I I 0 10 20 30 40 Frequency of Response (Number i n brackets=frequency) .1 50 119 I I . MESSAGE BELIEF SCORES COMPARED BY SOURCE Although not d i r e c t l y r e l a t e d to the re s e a r c h design, i t was f e l t to be of i n t e r e s t to compare the a c t u a l mean b e l i e f i n message scores f o r each source, these are l i s t e d i n the Table XV. Table XV - Mean B e l i e f i n Message Scores Grouped By Source Source No. Mean Standard D e v i a t i o n Number i n Group 1. N u t r i t i o n i s t 4.42 1 .74 30 2. Food S c i e n t i s t 4.39 1 .53 32 3. Medical Doctor 4.18 1 .46 33 4. C o n t r o l 4.21 1 .96 30 O v e r a l l 4.33 1 .66 125 From t h i s t a b l e i t can be seen that the mean score f o r b e l i e f i n the pro-food a d d i t i v e statement d i d not vary a great d e a l between the sources. T h i s was expected f o r sources 1, 2 and 3, as a l l were p r e v i o u s l y r a t e d as h i g h l y c r e d i b l e . However i t i s i n t e r e s t i n g to note that the c o n t r o l source , that i s , no source at a l l , appeared to be as e f f e c t i v e as the c r e d i b l e s o urces. A l s o , the mean b e l i e f scores were very c l o s e to 4 , i n d i c a t i n g t h a t o v e r a l l , respondents remained undecided about t h e i r b e l i e f i n the pro-food a d d i t i v e message, r e g a r d l e s s of the source. In t h i s v e i n , i t was f e l t to be of i n t e r e s t to examine the a c t u a l scores f o r b e l i e f i n the message, and how these scores v a r i e d for the sources over a t t i u d e ranges of a n t i , undecided and pro-food a d d i t i v e . 120 The mean a t t i t u d e scores were groupd i n t o three l e v e l s : L e v e l 1 (0-3.49) L e v e l 2 (3.50-4.50) L e v e l 3 (4.51-7.0) The mean b e l i e f score was then determined f o r each a t t i t u d e l e v e l , and f o r each source. The r e s u l t s are l i s t e d i n Table XVI . Table XVI - B e l i e f i n Message Over Three A t t i t u d e L e v e l s MEAN ATTITUDE SCORE Le v e l 1 Level2 Level3 O v e r a l l Source (0-3.49) (3.50-4.50) (4.51-7.0) A n t i N e u t r a l Pro N u t r i t i o n i s t 3.94 4.80 4.75 4.42 Food S c i e n t i s t 3.59 5.43 5.19 4.39 Medical Doctor 3.10 4.00 5.56 4.18 C o n t r o l 2.63 5.27 5.61 4.21 O v e r a l l 3.36 4.73 5.29 4.30 These r e s u l t s were then graphed to gi v e an o v e r a l l p i c t u r e of the a c t u a l mean scores of the sample, as shown i n F i g u r e 6. T h i s was done because the treatment r e g r e s s i o n planes i n d i c a t e d that none of the sources r e s u l t e d i n an o v e r a l l b e l i e f i n the message, whil e , from the frequency histograms i t was c l e a r that some of the respondents d i d indeed b e l i e v e the message. From the graph ( F i g u r e 6.), the t r e n d towards g r e a t e r b e l i e f i n the 121 message as a t t i t u d e becomes more p o s i t i v e can be seen. Respondents with negative a t t i t u d e s toward food a d d i t i v e s tended not to b e l i e v e the message. T h i s was the same t r e n d shown i n the graph of r e g r e s s i o n p l a n e s . For the undecided respondents however, there i s a more p o s i t i v e e f f e c t of the sources, with the c o n t r o l and food s c i e n t i s t c a u s i n g g r e a t e r b e l i e f than the medical doctor or c o n t r o l . But there i s indeed an i n d i c a t i o n of b e l i e f i n the message, i . e . a score g r e a t e r than 4.5, which was not evident i n the r e g r e s s i o n plane graph. And, people with p o s i t i v e a t t i t u d e s towards food a d d i t i v e s d i d indeed b e l i e v e the pro-food a d d i t i v e message, whereas i n F i g u r e 2, t h i s b e l i e f was not e v i d e n t . T h e r e f o r e , some people a c t u a l l y b e l i e v e d the message, a c c o r d i n g to the mean s c o r e s . However, t h i s graph ( F i g u r e 6) c o n s i d e r s o n l y three p a r t i c u l a r p o i n t s out of a l l the data, which makes e x t r a p o l a t i o n to the general sample d i f f i c u l t . In a d d i t i o n , due to l a c k of s u b j e c t s , i t was not p o s s i b l e to s t a t i s t i c a l l y t e s t the the s i g n i f i c a n c e of the d i f f e r e n c e between the four sources. The g e n e r a l assessment of the e f f e c t s of source must be c o n s i d e r e d i n l i g h t of the f u l l r e g r e s s i o n model, F i g u r e 2. 122 F i g u r e 6 - Graph of Message B e l i e f v s . A t t i t u d e L e v e l 7 r CD u o o c rt CD S CD 60 rt 01 in CJ C • H 4-1 CD CD CO 3 U Nutritionist Food Scientist Medical Doctor Control 1 J Level 1 (0 - 3.49) Level 2 (3.50-4.50) Level 3 (4.51-7.00) Attitude Levels (Unfavourable, Undecided, Favourable) 123 V. SUMMARY AND CONCLUSION The r e s u l t s of t h i s r e s e a r c h supported surveys r e p o r t e d i n the l i t e r a t u r e t h a t found the presence of negative a t t i t u d e s toward food a d d i t i v e s . Of the respondents, 42.4% expressed negative a t t i t u d e s toward food a d d i t i v e s , while an a d d i t i o n a l 32% were undecided. One of the g e n e r a l o b j e c t i v e s of t h i s r e s e a r c h was to determine the more c r e d i b l e sources of i n f o r m a t i o n on food a d d i t i v e s . A n u t r i t i o n i s t , a food s c i e n t i s t and a medical doctor were r a t e d the three most c r e d i b l e sources. However, t h i s r a t i n g was completed by a small and perhaps b i a s e d sample, and a more g e n e r a l i z e d r a t i n g by the p u b l i c i s yet r e q u i r e d . In a d d i t i o n , other s o u r c e - r e l a t e d f a c t o r s , such as the medium with which the sources are a s s o c i a t e d would c e r t a i n l y i n f l u e n c e the e f f e c t i v e n e s s of these sources i n any p u b l i c communication. T h i s a l s o remains to be examined. The second and t h i r d g e n e r a l problems i n c o u n t e r a c t i n g m i s i n f o r m a t i o n about food a d d i t i v e s were examined by determining whether or not the source of a pro-food a d d i t i v e message would i n f l u e n c e b e l i e f i n the message; and whether or not the a t t i t u d e of the message r e c e i v e r towards food a d d i t i v e s would i n f l u e n c e t h e i r b e l i e f i n the pro-food a d d i t i v e message. Th i s r e s e a r c h found a s i g n i f i c a n t i n t e r a c t i o n e f f e c t between the source of the message and the a t t i t u d e of the message r e c e i v e r toward food a d d i t i v e s . Of those respondents i n the sample who h e l d negative a t t i t u d e s toward food a d d i t i v e s , the n u t r i t i o n i s t appeared to cause g r e a t e r b e l i e f i n the pro-124 food a d d i t i v e message. For those who were undecided about food a d d i t i v e s , the food s c i e n t i s t seemed s l i g h t l y more e f f e c t i v e than the other sources. An i n t e r e s t i n g r e s u l t here was that the e f f e c t of the n u t r t i o n i s t on b e l i e f i n the message remained r e l a t i v e l y c o n s t a n t , r e g a r d l e s s of the a t t i t u d e of the message r e c e i v e r . None of the sources were o u t s t a n d i n g l y s u p e r i o r to the other sources i n t h e i r e f f e c t on b e l i e f i n the message T h i s was expected, as a l l three sources were p r e v i o u s l y r a t e d as h i g h l y c r e d i b l e . Although the e f f e c t s of r e c e i v e r a t t i t u d e and message source were s i g n i f i c a n t , these two v a r i a b l e s d i d not c o n t r i b u t e much to the o v e r a l l accountable v a r i a n c e i n b e l i e f i n the message. T h i s may have been due to the instrument used, or perhaps i t i n d i c a t e s that other f a c t o r s are more i n f l u e n t i a l . T h i s study found that communicating a message that i s c o n t r a r y to popular b e l i e f s about food a d d i t i v e s remains somewhat of a problem, i n s p i t e of using h i g h l y c r e d i b l e sources of i n f o r m a t i o n . For people with negative a t t i t u d e s toward food a d d i t i v e s , none of the sources used i n the study were i n f l u e n t i a l enough to produce b e l i e f i n the pro-food a d d i t i v e message. R e s u l t s from t h i s r e s e a r c h support Delaney and Maxwell (1980) i n f i n d i n g t h at the use of a c o v a r i a t e term (under c e r t a i n c o n s t r a i n t s ) i n the r e g r e s s i o n model produced a s i g n i f i c a n t a t t r i b u t e by treatment i n t e r a c t i o n . T h i s i n t e r a c t i o n has been somewhat i l l u s i v e i n other models. 125 I t i s recommended that care be taken i n the design of instruments measuring a t t i t u d e s toward food a d d i t i v e s . Statements that appear to be open to o p i n i o n , may be taken f o r f a c t , due to the e f f e c t of a s t e r e o t y p e image about food a d d i t i v e s . A l s o , the use of statements and measurement s c a l e s which have d e n o t a t i v e c h a r a c t e r i s t i c s must be avoided. The q u e s t i o n of what i s the most e f f e c t i v e way to c o u n t e r a c t m i s i n f o r m a t i o n about food a d d i t i v e s remains a d i f f i c u l t one to answer. There are many v a r i a b l e s i n v o l v e d i n the s o l u t i o n to t h i s problem. T h i s r e s e a r c h has shed some l i g h t on two v a r i a b l e s : the source of r e l i a b l e i n f o r m a t i o n about food a d d i t i v e s and the message r e c e i v e r ' s a t t i t u d e toward food a d d i t i v e s . Much work remains to be i n v e s t i g a t e d r e g a r d i n g the most e f f e c t i v e means f o r c o u n t e r i n g .misinformation, i n c l u d i n g such v a r i a b l e s as message s t r u c t u r e , type of media used, and l e v e l of involvement i n the food a d d i t i v e i s s u e . I f c r e d i b l e sources are i n e f f e t i v e at changing a t t i t u d e s toward food a d d i t i v e s , then perhaps other avenues w i t h i n a t t i t u d e change theory need to be e x p l o r e d . A P P E N D I X A - P R E - S U R V E Y O N E 127 SOURCE CREDIBILITY THIS SURVEY IS DESIGNED TO ASSESS THE APPLICATION OF SOURCE CREDIBILITY THEORY TO A SPECIFIC TOPIC. THE RESULTS OF YOUR PARTICIPATION WILL AID IN THE UNDERSTANDING OF THIS ASPECT OF COMMUNICATING SCIENTIFIC INFORMATION TO THE PUBLIC. YOU ARE FREE TO WITHDRAW AT ANY TIME, OR TO REFUSE TO ANSWER ANY QUESTIONS WITHOUT PREJUDICE. REFUSAL TO PARTICIPATE WILL, IN NO WAY AFFECT CLASS STANDING . IF THE QUESTIONAIRE IS COMPLETED, IT WILL BE ASSUMED THAT CONSENT HAS BEEN GIVEN. PLEASE DO NOT SIGN YOUR NAME. THE TIME ALLOTTED IS FIFTEEN (15) MINUTES. IN THE SURVEY. YOU ARE ASKED TO RATE SEVERAL SOURCES OF FOOD ADDITIVE INFORMATION BY RESPONDING ON A SEMANTIC DIFFERENTIAL SCALE . A FOOD ADDITIVE IS A SUBSTANCE ADDED INTENTIONALLY TO A FOOD THAT ALTERS THE CHARACTERISTICS OF THAT FOOD . FOR EXAMPLE, STABILIZERS, COLOURS AND PRESERVATIVES ARE FOOD ADDITIVES. THERE HAS BEEN EXTENSIVE REPORTING OF FOOD ADDITIVE ISSUES IN THE MEDIA IN RECENT YEARS. PARTICULARLY THEIR EFFECTS ON HEALTH. PLEASE CONSIDER THESE SOURCES OF INFORMATION WHEN RESPONDING TO THE'FREQUENCY OF USE1 QUESTION THAT FOLLOWS EACH SET OF ADJECTIVE PAIRS. THANK YOU FOR YOUR PARTICIPATION IN MY THESIS RESEARCH PROJECT . SINCERELY. Shelagh Campbell SOURCE CREDIBILITY INSTRUCTIONS IN THIS SURVEY, A SOURCE WILL BE NAMED, FOLLOWED BY SIX ADJECTIVE PAIRS, AND A FREQUENCY OF USE QUESTION. YOU ARE REQUESTED TO CHOOSE THE ONE WORD FROM EACH ADJECTIVE PAIR THAT BEST DESCRIBES YOUR FEELINGS ABOUT THE SOURCE, AND THEN TO INDICATE HOK CLOSELY RELATED THE WORD IS TO YOUR FEELINGS. THIS IS INDICATED BY HOK CLOSELY "X " IS PLACED TO THE CHOSEN WORD. FOR EXAMPLE. CONSIDER THE NAMED SOURCE. IS THIS SOURCE OF INFORMATION REGARDING FOOD ADDITIVES TRUSTWORTHY OR UNTRUSTWORTHY ? A NEIGHBOR trustworthy PROVIDING INFORMATION ABOUT FOOD ADDITIVES. untrustworthy X ! I I 1 1 1 I I ! equally j i - - - s l i g h t l y -i ' quite c l o s e l y — SAY, FOR THIS EXAMPLE, TRUSTWORTHY BEST DESCRIBES YOUR FEELINGS ABOUT THE SOURCE . NEXT, DECIDE IF THE SOURCE IS VERY TRUSTWORTHY. QUITE TRUSTWORTHY OR ONLY SLIGHTLY TRUSTWORTHY . IN THIS EXAMPLE, S l i g h t l y trustworthy IS MARKED. IF THE SOURCE IS EQUALLY TRUSTWORTHY AND UNTRUSTWORTHY, THE CENTRE SPACE IS MARKED . PLEASE COMPLETE ALL SIX ADJECTIVE PAIRS AND THEN ANSWER THE QUESTION: HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? ALL X NONE PLEASE INDICATE THE APPROXIMATE POSITION ON THE SCALE BETWEEN "ALL" AND "NONE" THAT CORRESPONDS TO THE PORPORTION OF WHAT YOU HAVE HEARD ABOUT FOOD ADDTTIVES THAT ORIGINATED FROM THIS SOURCE. THE MID SPACE MEANS THAT HALF OF WHAT HAS BEEN HEARD ABOUT FOOD ADDITIVES COMES FROM THIS SOURCE. 129 MEDICAL DOCTOR PROVIDING INFORMATION ABOUT FOOD ADDITIVES. (A DOCTOR WITH A RECOGNIZED MEDICAL DEGREE) COMPETENT INCOMPETENT INEXPERIENCED . EXPERIENCED D1SHOKST TRUSTWORTHY UNTRUSTWORTHY UNSYMPATHETIC SYMPATHETIC TRA1 SEP UNTRAINED HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? ALL » * A FOOD SCIENTIST PROVIDING INFORMATION ABOUT FOOD ADDIT IVES (A PERSON WITH A SCIENCE DEGREE IN THE CHEMISTRY OF FOOD AND FOOD PROCESSING) COMPETENT INCOMPETENT INEXPERIENCED EXPERIENCED DISHONEST ; HONEST TRUSTWORTHY' UNTRUSTWORTHY' UNSYMPATHETIC SYMPATHETIC TRAINED UNTRAINED HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? ALL * > * 130 A r n ^ i M T P REPORT ER PROVIDING .INFORMATION ABOUT FOOD ADDITIVES (A JOURNUIST WHO SPECIALIZES IN AREAS OF INTEREST TO CONSUMERS) COMPETENT INCOMPETENT INEXPERIENCED . EXPERIENCED HONEST DISHONEST UNTRUSTWORTHY TRUSTWORTHY , UNSYMPATHETIC SYMPATHETIC TRAINED ' UNTRAINED HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? ALL » * A rr.VM.MFKr SPOKESMAN PROVIDING INFORMATION ABOUT FOOD ADDITIVES (A PERSON REPRESENTING A GOVERNMENT DEPARTMENT, WHOSE JOB IS TO PROVIDE INFORMATION TO THE PUBLIC) COMPETENT INCOMPETENT INEXPERIENCED . EXPERIENCED HONEST DISHONEST - . _ „ _ . u . . UNT RUST WOW WY TRUSTWORTHY - — — — — UNSYMPATHETIC SYMPATHETIC TRAINED UNTRAINED HOW MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? ALL NONE 131 AN ANNONYMOUS REPORTER PROVIDING INFORMATION ABOUT FOOD ADDITIVES (THE REPORTER IS FROM A FIELD NEKS SERVICE, BUT NOT NAMED) COMPETENT INCOMPETENT INEXPERIENCED _ _ . EXPERIENCED DISHONEST HONEST TRUSTWORTHY UNTRUSTWORTHY UNSYMPATHETIC SYMPATHETIC TRAINED UNTRAINED HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDIT IVES CAME FROM THIS SOURCE ? ALL » * A NUTRITIONIST PROVIDING INFORMATION ABOUT FOOD ADDITIVES (A PERSON WITH A SCIENCE DEGREE IN THE UTILIZATION OF FOOD NUTRIENTS BY THE HUMAN BODY) COMTET ENT INCOMPETENT INEXPERIENCED EXPERIENCED DISHONEST HONEST TRUSTWORTHY- UNTRUSTWORTHY' UNSYMPATHETIC SYMPATHETIC TRAINED UNTRAINED HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? ALL NONE 132 A HEALTH FOOD ADVOCATE PROVIDING INFORMATION ON FOOD ADDITIVES (A PERSON WHO PROMOTES ADDITIVE-FREE. UNREFINED FOODS) COMPETENT INCOMPETENT INEXPERIENCED EXPERIENCED DISHONEST HONEST TRUSTWORTHY' UNT RUST WORTHY UNSYMPATHETIC SYMPATHETIC TRAINED UNTRAINED HOK MUCH OF WHAT YOU HAVE HEARD ABOUT FOOD ADDITIVES CAME FROM THIS SOURCE ? NONE A P P E N D I X B - P R E - S U R V E Y TWO 134 THESIS RESEARCH - Pre-survey May 7,1982 The prupose of t h i s e x e r c i s e i s t o dertermine the r e l a t i v e • p o s i t i o n s o f a s e r i e s o f statements; i n other words, how STRONGLY NEGATIVE or how STRONGLY POSITIVE the s t a t e n e n t s a r e . Please DO NOT c o n s i d e r the t r u t h f u l n e s s , or whether or not you agree or d i s a g r e e w i t h the statements. There are no r i g h t or wrong responses The s c a l e on which the statement i s r a t e d has a range o f 7 p o i n t s . Please i n d i c a t e o n l y one p o i n t i n response t o the statement on the card. very s t r o n l y n e g a t i v e n e u t r a l q u i t e n e gative s l i g h t l y n e g a tive very s t r o n g l p o s i t i v e q u i t e p o s i t i v e s l i g h t l y p o s i t i v e r „ . .».„ Bi- i f vou f e l t t h a t "Food a d d i t i v e s make people happy'.' Sit!"Ttitlve'statemenJ. mark the X i n the corresponding p . i . t . was CARD NUMBER 135 1 0 . 1 1 . 1 2 . 1 3 . 14. 15. 16. 17. 18. 19. 20. 21. 22. APPENDIX C THE MAIN SURVEY 137 SOURCE CREDIBILITY . v- «rmiication o f touTce c r e d i b i l i t y T h i s q u e s t i o n a l i » designed to a s s e s , the a p p l i e d < The r e , u l t . o f your p a r t i c i p a t i o n w i l l * the under-theory t o . . P « i f i c t o p i c . The r e s u l t . l a n d i n g o f t h i s aspect o f communicating . c i e n t i f . c research There . r e three par ts to the q u e s t i o n a l : Part 1 Your Opinions P a n 2 The Message Part 3 Your Reaction to the Message. In Part 1, you are requested t o judge a se r i e s o f statements and respond on the sca le p rov ided . There are no r i gh t or wrong answers. In Part 2, j us t read the b r i e f message, keeping i n B ind tne KRITER o f the atessage. In Part 3, the invest-i g a to r i s in te res ted i n your r eac t i on t o the cessage. A s ca l e i s provided fo r your response F i f t e en minutes are a l l o t t e d f o r t h i s survey. You are f ree t o withdraw at any time or re fuse t o answer any quest ions without p r e jud i ce . I f the quest iona i rc i s completed, i t w i l l be assumed that consent has been g i ven . Please do not s ign youT name. Refusal to p a r t i c i p a t e w i l l i n no way a f f e c t c l a s s s tanding. Thank you f o r your p a r t i c i p a t i o n i n my thes i s research p ro j e c t . S i n c e r e l y , Shelagh Campbell 138 PART 1 YOUR OPINION Please i nd i ca t e your f e e l i n g s about the statement by p l a c ing an "X" on the s c a l e between p a i r s o f a d j e c t i v e s . Your should p lace one *'X" between each pa i r o f words according t o how c l o s e l y r e l a t e d your f e e l i n g s are t o that word. Choose which o f the two words i n the ad jec t i ve p a i r best desc r ibe your f e e l i n g s . Then, decide i f your f e e l i n g ; are very c l o s e l y r e l a t ed t o t h i s word, qu i t e c l o s e l y , or only s l i c h i l y r e l a t e d . I f your f e e l i n g s are equa l l y r e l a t e d t o both words, mark the centre space. For example : FOOD ADDITIVES PROTECT FOOD FROM SPOILAGE. IMPROBABLE equa l l y s l i g h t l y -'-quite c losely-— v e r v c l o s e l y r e l a ted-PROBABLE The -X" p l-ced as above i nd i ca tes that the respondent f e e l s the statement i s qu i t e probab le . FOOD ADDITIVES ARE ADEQUATELY CONTROLLED LI KIT ' d lUtt lT IWR0U1LI WOIUU YUE , U S l IWCSSIILI — » S S 1 I 1 I FC]SL WOUSH GOOD ' • » SICK KMTHY HARMFUL KK1F1CIA1 1.1 ULV IWROUllI WOSAIU TRUE »*>•« itrossnu _ rossiiu KISl ecoD •*» SICK Munm mmnau. ; «**wui FOOD ADDITIVES ARE A SERIOUS RISK TO HEAUH UQl* INPWSAILE . TSUE i i r o s s i t u USE GOOD SICK VN-IOLY rwsASU FALSE FOSSIILE FOOLISH SAD HEAITHY HARMFUL FOOD ADDITIVES CAUSE CANCER 11ULY INPROIAILI , TRUE IHKSS1ILE MSE COOD SICK iicnaAL UttlttLY MOIAILE FALSE FOSSIILE FOOLISH SAD • A » H V HARMFUL 141 FOOD ADDITIVES ARE HARMLESS tnuaiv u r n * noMiix t w u u i u — — — -FALSI TRUE _ _ — — MSSIILE 1NP05SIILE — FOOLISH K1SE — SAD GOOD — — — « « — K U J K V HARMFUL BENEFICIAL _ _ — — — FOOD ADDITIVES ARE NECESSARY IN FOOD uaLV BHiair IK»RO»A»LE W 0 U , U TRUE 1MFOSS1ILE »OSSl»LE VISE COCD • » » Hi ALT m SICk _ — — — — HARMFUL BENEFICIAL — — 142 PART 2 THE MESSAGE Please read the fo l lowing message: Additive panic unfounded With the barrage of Infemotlon and conflicting edvlea cealng at ui these days. It's nosy to aacoae uncertain about tfM food »• oat. Understanding tha Ingradlonta on •oat food labels n m to require • dagraa In eheelstry. Tat tha rlak f r o * these difficult to pro-nounce ehealeel addltlvas ftaa been greatly exaggerated. According to Or. Retort truea, Naad of tha Ludwig Institute for Canoar Kaaaareh In Toronto, •Studies Indleata that 70-791 per-cent of teaale canoan arc ralatad to dietary liabtta. Dy coaparlson, radiation, arugs, food addltlvai and occupational hazards ara alnor And, Dr. Elliabotti Vhelen, Exe-cutive Olractor of the American Council on Selanea and Health goat •van furthar: "There la aot on* alngla caaa on record of any huann deoth related to tha oonsuaptIon of food additives.* So, etiy a l l tha worry? When eoaa additives have baeoae suspect or actually banned, ee've natural-ly overreacted end luce— eegatlve on alaott al l additives. In feet, •e'va forgotten about tha bsneflta - benefits that aaan enough food for large urban popu let Ions that •••and a elde variety of eons la-tently high quality, safe nutrit i -ous end convenient foods. In addition, our oanaeras about food are exploited by tha aedla •ho frequently point a eery one-*Ifed picture. The fact that ejddltlves are rigorously tested •Ond strictly control led by lav -*tha Food and Drugs Act end Regula-tions - Is rather out I Inforoatlon esoaeered to tha frightening eoare # tor I as that appear la newspapers jond aegulaae. Even food nenufecturen aelvas have caused confusion by rassvlng herelass additives In order to sell •eddltlve-free" pro-euct*. More than a few ceapanlas, for Instance heva stopped adding propionate to their braad.But, In fact, propionate Is a safe sub-stance thet's eatural ly present (et even higher levels) In Swiss cheese. It retards the growth of ha ref u I ecu Ids on breed. The one basic Ingredient that aeons to be B i a s i n g free aeny food additive Issues Is cue sun sense. It's too bad, for without el I the Ingredients, tha concerns on) up beIf baked. John Johnston (Editors note: nutritionist) John Johnston Is a 143 PART S YOUR REACTION TO THE MESSAGE A f t e r reading the message, p lease i nd i ca t e your r e a c t i on t o the in fo rmat ion , keeping i n mind the source o f the message. Again there are p a i r s o f ad jec t i ves and you are requested t o choose the one word from esch p a i r that best descr ibes your r e a c t i o n , and then t o i nd i ca te how c l o s e l y r e l a t e d the word i s t o your r e a c t i o n . T h i s i s i nd i ca ted by how c l o s e l y the "X " i s p laced t o the chosen word. For example, cons ider the information presented i n the message, has i t poss ib l e o r imposs ib le ? pos s i b l e impossible equa l l y J — s l i g h t l y — J qu i te c l o s e l y -very c l o s e l y re la ted-Say, f o r t h i s example, ^>ossible"best desc r ibes your r eac t i on to the informat ion presented i n a message. Next, decide i f i t i s very poss ib l e , qu i te p o s s i b l e , or s l i g h t l y p o s s i b l e . In t h i s example 'quite p o s s i b l e " i s mai led. I f the informat ion presented i s equa l ly poss ib l e and imposs ib le , the centre space i s marled. Please complete a l l e ight ad jec t i ve p a i r s . Aga in , there are no r igh t o r wrong answers. 144 PART 3 YOUR REACTION TO THE MESSAGE What is your reaction to the information in the message ? Place an "X" in the appropriate space for each adjective pair. LIKELY UNLIKELY IMPROBABLE PROBABLE POSSIBLE IMPOSSIBLE FALSE TRUE DISAGREE AGREE THANK YOU, THE QUESTIONAIRE IS NOW COMPLETED. LEAVES 145 to 147 DUPLICATES OF PAGE 142. 145 PART 2 THE MESSAGE Please read the fo l lowing message: Additive panic unfounded With th* barrage of Information and conflicting advice coalng at wt that* days, It't easy to beeoee uncertain about tn* food ** H t , Understanding th* Ingredient* on •est food labels asset to require • degree In cnealstry. Vat the rlak fro* that* difficult to pro-neunet cheelcal additives net been greatly exaggerated. According to Dr. Robert •rue*, H*ad of th* Ludvlg I tat I tut* for Cancer Research In Toronto, •Studies Indicate that 70-75* per-cent of few I* cancers are related to dietary habits. By coaparleon, radiation, drugs, food additives and occupations! hazard* are alnor causes". And, Or. Elizabeth Hholan, Ear-out I»» Director of th* American Council on Selenea and Health goes •yen further) There Is act one • Ingle cat* on record of any huaen eeath ralat*d to th* oantuoptlon of food additives." So, atiy al I th* •orryT When K M additives have baeoaa autpaet or actually banned, we've nature I -ly overreacted and tecoa* negative on alaost a l l additives. In tact, •a'va forgotten about the benefits - benef I ts that a*an enough food for large orban populations that aaeand a aide variety of cons la-tently nigh auallty, aefe eutr I f l -out and convenient foods. In addition, our eon pares about food are exploited by tea aadla •ho frequently paint a vary one-sided picture. The fact that additives are rigorously tasted and etrlctly controlled by lev -the Food and Drugs Act and Regula-tions - Is rather eull Interest Ion •capered to the frightening scare stories that appear ia aamaapera •ad aegetlaes. Even food aanufaeturert •elvas have caused confusion by removing harmIest additives In order to sell "additive-free* pro-ducts. Mora than a fee cos pen I at, for Instance hev* stepped adding propionate to their bread .But, In fact, propionate Is a ssfe sub-stanot that'* natural ly present (et even higher levelsl In Svltt cheese. It retardt the growth of haraful em Ids on bread. The one tatlc Ingredient that •aees to be elsslng free esny food additive Issues Is easn sens*. It's too bad, for without all the Ingredients, tta concern* end up half baked. John Johnston (Editors eote: aodlcal doctor) John Johnston Is a 146 PART 2 THE MESSAGE Please read the fo l lowing message: Additive panic unfounded • Ith the barrage of Information and conflicting ad vies aoalng at •t these ears, It's oasy to bacons •ncerteln about tha food on ant. Understanding tha Ingredients an east food lab* It a* no to require a degree In ehealttry. Vet tha risk fro* these difficult to pro-•ounce oheelcel additives ess bean greatly exaggerated. According to Dr. Robert •rues. Need of the Udelg Institute for Ceneer Raseereh In Toronto, •Studies Indicate that TO-TSf per-cent of fee* I a esnoars are related to dietary habits, ty Comparison, radiation, fk-ugs, food additives and occupations! baierS are el nor anuses'. And, Dr. tlltabtth Nhelen, fan-out Ive Director of the Anerleon Council on Science and NeeIth (set even furtheri "There Is not one Single ease on record of any buaan ••ith /elated to tha eonsueptIon of food additives.* • So, stty nl I the •orryT When none additives have becoae nut pact 'or actually bsnnad, ae've anturel-ly ewreected and becona negative •n alnost a l l additives. In fact, 'we've forgotten about the benefits benefits that aaan enough food for (nrga air ban populations that .ejeeerx) a vide variety ad eons la-tently high quality, acta nutr i t i -ous and convenient foods, ' In addition, aur aanearns about .food are exploited by tha madia *»ho frequently paint a eery •.•ne-sleed picture. The fact that (additives am rlgorouily tea tad fpjnd Strictly aontrol led by «ew • Jfhe Food and Drugs Act and Regula-te lone - la rather bull lafcreation Caoapered to tea frightening scare Jatorlee that asaeer In P*d aegezlaae. Evan food aenvfacturers than •elves bava caused confusion by ranovlng heraless additives In order to sell •eddltlve-free* pro-duct*. Nora than a fe* compsnlet, for Instance have stepped adding propionate to their bread Ju t , In fact, propionate Is a aefe sub-stance that's nature) ly present let even higher levels) In Sales •heese. It retards tha growth of harefuI aouidt on breed. The one telle Ingredient that aaeas to bs olsslng fron aeny food additive Issues Is oaassn sense. It's too bad, for elthout alI tha Ingredients, the concerns and np naif ashed. John Johnston (Editors note: John Johnston is a sclent lit) 147 THE MESSAGE Please read the fo l lowing message: Additive panic unfounded Vlth th» barrage of Information and conflicting edvlot coning at at these days. If* eaty to become uneerteln about the food *» oat. Understanding the Ingredients an •est food labels eeena to require ' a degree In ehealttry. Vet the risk free these difficult to pro-nounce cheelcal additives has been greatly exaggerated. According to Dr. Robert •rue*. Mead of the Ludvlg Institute for Cancer Research In Toronto. •Studios Indicate that 70-7 W per-cent of fees I a csneors are related to dietary habits. By comparison, radiation, drugs, food additives and occupational hazards are el nor causes". And, Dr. Elizabeth Whelan, Exe-cutive Director of the American Council on Selenea and Health goes even furtheri There la not one elngle case on record of any human death related to the consumptIon of food additives." So, why a l l the eorryT Vhen so— additives have become suspect or actus I ly banned, we've natural-ly overreacted and become negative on almost all additives. In fact, . we've forgotten about the benefits • benefits that aaan enough food for large or ban populations that demand a aide variety of oonsls-tently high quality, aafe nutrit i -ous and convenient foods. In addition, our concerns about ; ' toed are exploited by the madia •ho frequently paint a eery one-sided picture. The fact that additives are rigorously tatted ;and strictly control ted by tew -the Food and Drugs Act and Regula-, f Ions - Is rather dull Information ^ camper ed to the frightening a core retort as that appear la newspapers t*Md eager lees. Even food manufacturers them aalvas have caused contusion by removing harmless additives In order to sell "additIve-tree" pro-ducts. More then a few ceapentts, for Instance have stopped eddlng propionate to their bread .But, In fact, propionate Is a aafe sub-stance that's natural ly present (at even higher levelt> In Saltt cheese. It reterdt the growth of harmful moulds on bread. The one bitIc Ingredient that seems to be alttlng from many food additive Issues Is common sense. It's too bed, for without al I the Ingredients, the concerns en) up half baked. 148 APPENDIX D - DEVELOPMENT OF THE SURVEY INSTRUMENTS I . PRESURVEY J_ " RATING OF SOURCES Table XVII - RATING OF SOURCES - ITEM STATISTICS Mean Score Per Item Competence Character SOURCE 1 2 3 4 5 6 Tot. M S.D. M S.D. M S.D. M S.D. M S.D. M S.D. M M.D. F. S. C R . G. S. A.R. Nutr H. F. 2 7 ,3 ,2 ,0 ,7 5. 6. 4. 4, 3, 6, 1 .3 1.2 1 .3 1 .8 1 .2 1 .1 5.9 1, 5.8 1 , 5.2 1 , 4.2 1 , 4.2 0, 3.9 1.2 4.4 1.1 0 0 3 0 7 5.9 1.2 4.6 1.0 5. 5. 4, 4, 3, 5, 0 1 4 3 , 1 ,2 4.8 1 4.9 1 4.7 1 3.8 1 4.3 1 5.6 1 1 2 5 2 0 3 5. 6. 4, 4, 3, 6, 5 1 6 6 4 2 5. 5, 4, 4, 3, 5. 3.9 0.9 5.1 1.4 2.8 1.3 4.1 (M = mean, S.D. Where: M.D. F. S. C R . G. S. A.R. Nutr, H. F. Standard D e v i a t i o n , Tot.= O v e r a l l mean score) Medical Doctor Food S c i e n t i s t Consumer Reporter Government Spokesman Annonymous Reporter N u t r i t i o n i s t H e a l t h Food Advocate Table XV11 povides f u r t h e r d e t a i l s about the c r e d i b i l i t y r a i n g s of the sources. The term 'item' r e f e r s t o the a d j e c t i v e p a i r used to r a t e c r e d i b i l i t y . Three a d j c t i v e p a i r s are used f o r competence and three f o r c h a r a c t e r . I t can be seen that the mean score f a r each item tends t o h i g h e s t f o r the n u t r i t i o n i s t , the food s c i e n t i s t and the medical doctor (the chosen sources) . I t i s i n t e r e s t i n g to note that the h e a l t h food advocate was ra t e d second o v e r a l l under the c h a r a t e r measure trustworthy/untrustworthy. 149 Table XVIII - Subtest S t a t i s t i c s - Source of Variance INDIVIDUAL ITEM RESIDUAL TOTAL DEGREES OF FREEDOM 21 5 105 131 SUMS OF SQUARES Medical Doctor 106.24 15. 24 70.76 192.24 Food S c i e n t i s t 50.64 28. 28 88. 18 167.64 Consumer Reporter 147.16 1 . 95 95.89 260.99 Government Spokesperson 56.24 7. 88 142.12 206.24 Annonymous Reporter 72.97 21 . 28 77.85 172.64 N u t r i t i o n i s t 66.52 7. 34 87.69 161.52 Hea l t h Food Advocate 47.52 65. 24 115.76 228.52 MEAN SQUARES Medical Doctor 5.06 3. 05 • 0.67 1 .47 Food S c i e n t i s t 2.41 5. 76 0.84 1 .28 Consumer Reporter 7.01 3. 59 0.91 1 .99 Government Spokesperson 2.68 1 . 58 1 .35 1 .57 Annonymous Reporter 3.47 4. 36 0.74 1 .32 N u t r i t i o n i s t 3.17 1 . 47 0.83 1 .23 He a l t h Food Advocate 2.26 13. 05 1.10 1 .74 I I . SCORING THE ATTITUDE MEASURE In the Fishbein-Raven (1967) a t t i t u d e / b e l i e f measure, the sub j e c t i s asked to respond t o a s e r i e s of statements by i n d i c a t i n g the a d j e c t i v e i n each p a i r that i s most c l o s e l y r e l a t e d to h i s or her f e e l i n g s evoked by the statement. 150 The t h e o r e t i c a l response to the statement i s o u t l i n e d by F i s h b e i n and Ajzen (1975). The statement c o n s i s t s of a su b j e c t (X), connected by an a s s e r t i o n , ( > ), to an o b j e c t (Y). The end response to the statement depends on the i n d i v i d u a l ' s f e e l i n g s toward each of the three p a r t s of the statement. T h i s assumes that the statement i t s e l f i s b e l i e v a b l e . ( F i s h b e i n and Raven, 1967) For example, the f o l l o w i n g a s s e r t i o n s connect o b j e c t s and s u b j e c t s , and r e s u l t i n the responses g i v e n : 1 ) + + - X X > Y good - - - - - - - bad Food a d d i t i v e s are bad. 2) - + X X > Y good - - - - - - - bad Food a d d i t i v e s are bad. 3) + + + X X > Y good - - - - - - - bad Food a d d i t i v e s are harmless. 4) - + X Food a d d i t i v e s are + > Y good harmless. X - bad 151 I f , as i n 1), I f e e l f a v o u r a b l y toward the s u b j e c t , food a d d i t i v e s , which i s connected by a p o s i t i v e a s s e r t i o n to an a b j e c t about which I am unfavourable, there i s i n c o n g r u i t y between the s u b j e c t and o b j e c t . The expected response i n t h i s example i s to mark an unfavourable p o s i t i o n i e 'bad'. In 2), I f e e l unfavourable toward food a d d i t i v e s , which i s conected to an o b j e c t toward which I am a l s o unfavourable, there i s no i n c o n g r u i t y . Hence the o v e r a l l r e a c t i o n to the statement i s f a v o u r a b l e , and the response i s 'good'. (The f a v o u r a b l e end of the s c a l e . ) In 3), the respondant i s f a v o u r a b l e toward food a d d i t i v e s , as w e l l as the o b j e c t , harmless. The statement i s congruent, and the o v e r a l l response i s f a v o u r a b l e and the favourable end of the s c a l e ismarked i e , 'good'. In statement 4), the example shows the respondant to be unfavourable toward food a d d i t i v e s , but i t i s connected to an o b j e c t toward which respondant i s f a v o u r a b l e . T h i s s t a t e of imbalance or i n c o n g r u i t y r e s u l t s i n an o v e r a l l unfavourable response to the statement, and the 'bad' end of the s c a l e i s marked. F i s h b e i n and Ajzen s t a t e that s c o r i n g i s conducted by awarding 7 to the p l a c e c l o s e s t t o the f a v o u r a b l e a d j e c t i v e p a i r , and 1 to the p l a c e c l o s e s t to the unfavourable a d j e c t i v e . Thus: 152 good 7 6 5 4 3 2 j_ bad h e a l t h y 7 6 5 4 3 2 1 s i c k wise 7 6 5 4 3 2 ] f o o l i s h b e n i f i c i a l 7 6 5 4 3 2 1 harmful In the four example statements above, a high a t t i t u d e score i n d i c a t e s a p o s i t i v e a t t i t u d e toward food a d d i t i v e s , while a low score i n d i c a t e s a negative a t t i t u d e toward food a d d i t i v e s . Responses to negative statements about food a d d i t i v e s can be p r e d i c t e d from t h i s theory. I f the respondant i s favourable towards food a d d i t i v e s , responses should r e s u l t i n a high a t t i t u d e s c o r e . The imbalance of the statement r e s u l t s i n marking the unfavourable end of the s c a l e , but, a score of 7 i s awarded as as the respondent i s f a v o u r a b l e toward food a d d i t i v e s . (1) + + x > Y Food a d d i t i v e s are bad 1 2 3 4 5 6 7 X wise - - - - - - - f o o l i s h X good - - - - - - - bad X h e a l t h y - - - - - - - s i c k X b e n i f i c i a l - - - - - - - harmful (2) Or, i f the respondant i s unfavourable toward food a d d i t i v e s , the response should r e s u l t i n a low a t t i t u d e score. The statement i s i n balance however, and the f a v o u r a b l e end of the s c a l e i s marked. But, i n t h i s case a score of 1 i s awarded for the f a v o u r a b l e s i d e . - + -X > y Food a d d i t i v e s are bad 1 2 3 4 5 6 7 X 153 wise - - - - - - - f o o l i s h X good - - - - - - - bad X h e a l t h y - - - - - - - s i c k X b e n i f i c i a l - - - - - - - harmful And, f o r the p o s i t i v e statements, the s c o r i n g i s reversed in order to maintain t h a t a respondant f a v o u r a b l e towards food a d d i t i v e s r e c e i v e s a h i g h score, while one who i s unfavourable r e c e i v e s a low s c o r e . A respondant who i s f a v o u r a b l e towards food a d d i t i v e s , i s expected to produce an o v e r a l l high a t t i t u d e s c o r e . The statement i s i n balance and the favourable end of the s c a l e i s i n d i c a t e d , r e c e i v i n g a score of 7. + + +X > y Food a d d i t i v e s are harmless 7 6 5 4 3 2 1 X wise - - - - - - - f o o l i s h X good - - - - - - - bad X h e a l t h y - - - - - - - s i c k X b e n i f i c i a l - - - - - - - harmful If the respondant i s unfavourable toward food a d d i t i v e s , an o v e r a l l low a t t i t u d e score i s expected. The statement i s not i n balance and the unfavourable end of the s c a l e i s marked. The unfavourable s i d e thus r e c e i v e s a score of 1. + + x > y Food a d d i t i v e s are harmless 7 6 5 4 3 2 1 X wise - - - - - - - f o o l i s h X good - - - - - - - bad X h e a l t h y - - - - - - - s i c k X 1 54 b e n i f i c i a l - - - - - - - harmful Th e r e f o r e , the s c o r i n g of the a t t i t u d e measure i s r e v e r s e d f o r the p o s i t i v e and negative statements. More p r e c i s e l y , f o r the p o s i t i v e statements: 6. Food a d d i t i v e s are necessary.; 5. Food a d d i t i v e s are harmless.; 1. Food a d d i t i v e s are adequately c o n t r o l l e d . ; the s c a l e i s scored as i n examples 3) and 4) above: + + + x > Y Food a d d i t i v e s are harmless 7 6 5 4 3 2 1 b e n i f i c i a l - - - - - - - harmful healthy - - - - - - - s i c k good - - - - - - - bad wise - - - - - - - f o o l i s h For the negative statements: 2) Food a d d i t i v e s d i s g u i s e i n f e r i o r products.; 3) Food a d d i t i v e s are a s e r i o u s r i s k . ; 4) Food a d d i t i v e s cause cancer. ; the s c a l e i s re v e r s e d , as i n examples 1) and 2) above. - + X > y Food a d d i t i v e s are bad 1 2 3 4 5 6 7 b e n i f i c i a l - - - - - - - harmful he a l t h y - - - - - - - s i c k good - - - - - - - bad wise - - - - - - - f o o l i s h 155 APPENDIX E - THE INSTRUMENT - ANALYSIS OF RELIABILITY I I I . STEPS IN INSTRUMENT DEVELOPMENT The f o l l o w i n g i s an assessment of the r e l i a b i l i t y t e s t i n g of the s c a l e s that were used to measure a t t i t u d e and b e l i e f i n the Main Survey. I t i s important to t e s t f o r r e l i a b i l i t y to ensure that the measurement instruments are not c o n t r i b u t i n g to e r r o r i n the r e s u l t s . I d e a l l y a l l accountable v a r i a n c e should be due to i n d i v i d u a l d i f f e r e n c e s i n the s u b j e c t s . The LERTAP (Laboratory of Education Research T e s t s A n a l y s i s Package) computer program generated s t a t i s t i c s t h at compared the c o r r e l a t i o n of each item ( a d j e c t i v e p a i r ) with the other items f o r each statement (sub t e s t ) and with the o v e r a l l measure of s i x statements that comprized the complete t e s t . From t h i s any items or statements that were d i f f e r e n t from the others c o u l d be observed. In a d d i t i o n , the HOYT R e l i a b i l i t y C o e f f i c i e n t was c a l c u a l t e d f o r each statement and f o r the o v e r a l l t e s t . The Hoyt R e l i a b i l i t y C o e f f i c i e n t i s based on the t r u e v a r i a n c e p l u s v a r i a n c e due to items d i v i d e d by t r u e v a r i a n c e p l u s unaccounted f o r v a r i a n c e . Mean Square Items (MSI) was a l s o c o n s i d e r e d i n the r e l i a b i l i t y assessment of the measurement instruments. MSI i s an i n d i c a t i o n of the amount of v a r i a n c e that i s due to items in the t e s t . T h i s f i g u r e should be low i n comparison to the mean squares f o r i n d i v i d u a l s and r e s i d u a l e r r o r . When MSI was r e l a t i v e l y h i g h , i n d i c a t i n g that the items were causing some problem, the t e s t was examined f o r p o t e n t i a l improvements. The assessment i s o u t l i n e d i n steps i n an attempt to 156 s i m p l i f y the procedures. Step 1a: The a t t i t u d e s c a l e , u s ing the complete t e s t ( a l l s i x statements y i e l d e d a good Hoyt (.87), but, i n the ANOVA, a very high mean square items (113.32) r e s u l t e d (Table XX1). S t e p l b : For the b e l i e f s c a l e , an unacceptable Hoyt (.58) and a very high mean square items i n the ANOVA r e s u l t e d (Table X X I I I ) . Step 2a: I t appeared as i f Item 1 on the a t t i t u d e measure f o r the ne g a t i v e statements was c o n s i s t e n t l y low (see Table XX). So, i n an attempt to improve the r e l i a b i l i t y of the instrument, item 1 was removed from the c a l c u l a t i o n of the s c o r e s . T h i s r e s u l t e d i n l i t t l e improvment, with Hoyt dropping to .85, and mean square items i n c r e a s i n g to 125.33 (Table XXIV). Step 2b: On the b e l i e f measure, i t appeared that Item 4 f o r the p o s i t i v e statements was c o n s i s t e n t l y higher than the other items (see Table X X I I ) . T h e r e f o r e , i n another attempt to improve the r e l i a b l i t y , Item4 was removed from the c a l a c u l a t i o n s of B e l i e f (X4), based on the scores f o r the pro-food a d d i t i v e statements o n l y . R e s u l t showed that Hoyt d i d not improve (.46), nor d i d mean square items (140.96) (Table XXVII). Step 3: From Tables XX and XXII, i t can be seen that the mean square items seemed t o d i f f e r depending on whether the statement was pro-food a d d i t i v e or a n t i - f o o d a d d i t i v e . For example: 157 A t t i t u d e Score B e l i e f Score Mean Mean Square Items Mean Mean Square Items P o s i t i v e 1 4.574 5.25 3.50 59.34 5 2.916 1.22 3.014 40.57 6 3.636 0.75 4.190 11.79 Negative 2 5.400 16.39 5.296 10.53 3 4.756 53.46 5.459 11.94 4 5.014 74.15 5.286 15.93 T h e r e f o r e , i n an attempt to improve the r e l i a b i l i t y of the t e s t , the measure was s p l i t i n t o two p a r t s : the Pro-Food A d d i t i v e Statements and the Anti-Food A d d i t i v e Statements. As can be seen i n Tables XXVIX, XXXI, Hoyts improve f o r both the a t t i t u d e measure (.90) and the B e l i e f measure (.88) f o r the pro statements. For the a n t i - s t a t e m e n t s , as shown i n Tables XXXIII and XXXV, the Hoyt R e l i a b i l i t y C o e f f i c i e n t s again improved to 0.89 f o r b e l i e f and 0.83 f o r a t t i t u d e . The mean square items a l s o improves to 64.81 f o r A t t i t u d e , and 62.18 f o r B e l i e f measure. Step 4a: From Table XXX, i t can be seen that f o r the p o s i t i v e statements, item.4 on the b e l i e f measure has c o n s i s t e n t l y higher mean scores that the other items i n the s u b t e s t . Item 4 was removed f o r improvement. When Item 4 i s removed, the Hoyt i s .85 and M.S. items i s much improved at 45.23, as shown i n Table XXXVI. Step 4b: From Table XXXII, i t can be seen that f o r the 158 negative statements Item 1 under the A t t i t u d e measure , had a c o n s i s t e n t l y lower mean score than the other items i n the s u b t e s t , as w e l l as a lower c o r r e l a t i o n with the other items i n the s u b t e s t . When iteml i s removed, Hoyt became.86 and M.S.items a h e a l t h y 8.62, as can be seen i n Table XXXVIX. Step 5: To r e i t e r a t e the s i t u a t i o n , the a t t i t u d e measure was very r e l i a b l e , only when negative statements were used, with iteml removed. In an attempt to improve the b e l i e f measure, i t was p o s t u l a t e d that those respondents who d i d not b e l i e v e the negative statements ( i e mean score <4), should be e l i m i n a t e d from the r e s u l t s . Only 9 respondents d i d not b e l i e v e the negative statements (13,19,26,53,54,63,90,104,124). As can be seen i n Table XXXXI, the r e l i a b i l i t y s t a t i s i t i c s d i d -indeed improve when these responses were d e l e t e d : Hoyt =.86 and M.S. items= 8 .18 f o r the B e l i e f Measure, and Hoyt=.84 and M.S. items=48.05 f o r the a t t i t i u d e measure (Table XXXXIII). Step 6: The t e s t f o r r e l i a b i l i t y of the Dependant V a r i a b l e , B e l i e f i n a Pro-food a d d i t i v e message , as shown i n Table XXXXIV, i n d i c a t e d the t e s t to be r e l e a b l e , with Hoyt = .96 and M.S.items=5.59. M u t l t i p l e Regression A n a l y s i s M u l t i p l e Regression was run using data based on the negative statements only t e s t , minus item 1 on the a t t i t u d e measure, n=116. U n f o r t u n a t e l y , a very low c o e f f i c i e n t of r e g r e s s i o n r e s u l t e d (R2=13.68) which d i d not account f o r any s i g n i f i c a n t amount of v a r i a n c e i n the dependant v a r i b a l e . 159 Step 7: Since the negative statements d i d not produce a s i g n i f i c a n t c o e f f i c i e n t of dete r m i n a t i o n (R2), a t t e n t i o n r eturned to the p o s i t i v e statements. The r e l i a b i l i t y t e s t and ANOVA were run on the p o s i t i v e statements, u s i n g the reduced sample (n=116). Both the b e l i e f and a t t i t u d e measures r e c e i v e d good Hoyts (.90 and .87 r e s p e c t i v e l y ) and f a i r Mean Square items (61.90 and 59.16 r e s p e c t i v e l y ) . However, these were not much b e t t e r than the same t e s t s on the whole sample (n=l25), where the a t t i t u d e measure r e c e i v e d Hoyt=.90 and MSI =64.81 , and, the b e l i e f measure r e c i e v e d Hoyt =.88 with MSI =62.18. B e t t e r r e l i a b i l i t y s t a t i s t i c s were obtained when item 4 on the B e l i e f measure was droppeed, r e s u l t i n g i n Hoyt=.85 and a b e t t e r MSI of 45.23. T h i s c o u l d be j u s t i f i e d only i n the case of the e n t i r e sample, where n=l25. I t was t h e r e f o r e decided t o analyze the f o l l o w i n g four types of data u s i n g m u t l i p l e r e g r e s s i o n : 1) n=116 2) n=125 (minus item 4 b e l i e f measure) 3) n=125 (with item 4 b e l i e f measure) 160 Table XIX - R e l i a b i l i t y of ATTITUDE MEASURE T o t a l Test Statement Item S t a t i s t i c s Mean S.D. C o r r e l a t i o n s s.t t . t MSI Hoyt S.E. 1. (Pro) Item 1 2 3 4 2. (A n t i ) 1 2 3 4 3. (A n t i ) 1 2 3 4 4. ( A n t i ) 6. (Pro) 1 2 3 4 (Pro) 1 2 3 4 4.73 4.75 4.32 4.50 4.88 5.70 5.42 5.61 3.79 4.94 5.06 5.23 2.94 3.03 2.90 2.79 3.72 3.54 3.62 3.66 2.13 2.1 1 1 .87 2.1 1 1 .77 1 .53 1 .42 1 .44 1 .82 1.71 1 .59 1 .60 0.85 0.85 0.79 0.88 0.67 0.85 0.73 0.77 0.58 0.77 0.71 0.76 0.66 0.68 0.61 0.61 0.41 0.46 0.40 0.44 0.38 0.50 0.35 0.35 1 .65 1 .75 1 .58 1 .62 1 .65 1 .69 1 .61 1 .72 0.79 0.90 0.91 0.92 0.87 0.93 0.83 0.87 0.52 0.56 0.47 0.50 0.51 0.48 0.44 0.55 5.25 0.89 7.41 16.39 0.79 6.85 53.45 0.74 7.98 1 3.89 1 .67 0.44 0.26 74. 15 2 5.29 1 .66 0.77 0.43 3 5.25 1 .52 0.70 0.31 4 5.63 1 .42 0.77 0.32 1.22 0.92 5.28 0.75 0.91 5.37 (MSI=mean square items; Item=adjective p a i r s of measurement s c a l e ; S,E.=standard e r r o r ; s.t.=sub t e s t , t . t = t o t a l t e s t ) i : — 161 Table XX - T o t a l Test S t a t i s t i c s - ATTITUDE Measure ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124 1916.50 15.46 Items 23 2614.80 1 13.69 Re s i d u a l 2852 6937.66 2.36 T o t a l 2999 11288.97 3.76 Hoyt=0.87 Standard Error=7.37 CORRELATIONS STATEMENT # 1 2 3 4 5 6 TOTAL TEST 1 1.00 0.23 0.11 0.15 0.33 0.37 .0.72 2 1 .00 0.46 0.33 -0.00 -0.04 0.54 3 1.00 0.56 -0.01 -0.03 0.53 4 1.00 -0.04 -0.14 0.46 5 1 .00 0.52 0.58 6 1.00 0.56 1 .00 162 Table XXI - R e l i a b i l i t y of BELIEF Measure T o t a l Test Statement Item* Mean Item S t a t i s t i c s S.D. C o r r e l a t i o n s s. t t . t MSI Hoyt S.E. 1. (Pro) 1 2.98 1 .63 0.83 0.40 59.34 0.81 7.55 2 3.48 1 .76 0.81 0.45 3 3.06 1 .79 0.85 0.42 4 4.48 1 .87 0.59 0.44 2. (An t i ) 1 5.21 1 .74 0.94 0.24 10.53 0.93 4.91 2 5.27 1 .69 0.94 0.23 3 4.98 1 .71 0.89 0.21 4 5.68 1 .32 0.80 0.29 3. (An t i ) 1 5.18 1 .61 0.91 0.06 1 1 .94 0.87 5.20 2 5.51 1 .38 0.90 0.13 3 5.27 1 .30 0.86 0.14 4 5.85 1.14 0.61 0.16 4. (An t i ) 1 5.12 1 .52 0.91 0.28 15.93 0.91 4.65 2 5.34 1 .46 0.91 0.30 3 4.93 1 .43 0.84 0.23 4 5.76 1.11 0.80 0.19 5. (Pro) 1 2.65 1 .76 0.71 0.26 40.57 0.79 8.26 2 2.78 1 .7-9 0.80 0.2'4 3 2.77 1 .76 0.78 0.27 4 3.86 2.09 0.70 0.37 6. (Pro) 1 4.14 1.81 0.94 0.45 1 1 .79 0.94 4.94 2 4.17 1 .77 0.93 0.48 3 3.86 1 .84 0.90 0.46 4 4.60 1 .69 0.86 0.50 163 Table XXII - T o t a l Test S t a t i s t i c s BELIEF i n Statements Measure ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124.00 756.70 6 .10 Items 23.00 3181.37 138 .32 Re s i d u a l 2852.00 7264.43 2 .55 T o t a l 2999.00 1 1202.50 3 .74 Hoyt=0.59 Standard Error=7. 58 CORRELATIONS Statement* 1 2 3 4 5 6 T o t a l Test 1 1 .00 -0.36 -0.39 -0.19 0. 40 0 .51 0.53 2 1.00 0.38 0.20 -0. 22 -0 .33 0.26 3 1 .00 0.57 -0. 52 -0 .43 0.14" 4 1 .00 -0. 42 -0 .26 0.29 5 1 . 00 0 .34 0.37 6 1 .00 0.51 T.T. 1 .00 164 Table XXIII -R e l i a b i l i t y of T o t a l T e s t , ATTITUDE Minus Iteml on A n t i ATTITUDE MEASURE Statement Item# Item S t a t i s t i c s MSI Hoyt S.E. Mean S.D. C o r r e l a t i o n s s.t t . t 1. (Pro) 1 4.73 2.13 0.85 0.64 5.25 0.89 7.41 2 4.75 2.11 0.85 0.60 3 4.32 1 .87 0.79 0.59 4 4.50 2.11 0.87 0.59 2. (An t i ) 1 2.56 0.82 6.16 2 5.70 1 .53 0.84 0.49 2 5.42 1 .42 0.83 0.46 3 5.61 1 .44 0.85 0.48 3. ( A n t i ) 1 2.75 0.79 7.38 2 4.94 1 .71 0.79 0.54 3 5.06 1 .59 0.83 0.44 4 5.23 1 .60 0.81 0.41 4. ( A n t i ) 1 5.57 0.80 6.76 2 5.29 1 .66 0.79 0.45 •• 3 5.25 1 .52 0.82 0.41 4 5.63 1 .42 0.87 0.40 5. (Pro) 1 2.94 1 .65 0.79 0.52 1 .22 0.92 5.28 2 3.03 1 .75 0.90 0.56 3 2.90 1 .58 0.91 0.50 4 2.79 1 .62 0.92 0.50 6. (Pro) 1 3.72 1 .65 0.87 0.51 0.75 0.91 5.37 2 3.54 1 .69 0.93 0.48 3 3.62 1 .60 0.83 0.44 4 3.66 1 .72 0.87 0.55 165 Table XXIV - Test S t a t i s t i c s - ATTITUDE - Minus Iteml on A n t i ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124 1852. 92 14.94 I terns 20 2506. 60 125.33 R e s i d u a l 2480 5659. 79 2.28 T o t a l 2624 10019. 30 3.82 Hoyt=0.85 Standard Error=6. 76 CORRELATIONS Statement* 1 2 3 4 5 6 T o t a l Test 1 1 .00 0.25 0.09 0.14 0 .33 0.37 0.70 2 1.00 0.50 0.39 -0 .02 -0.07 0.55 3 1 .00 0.57 -0 .06 -0.06 0.55 4 1 .00 -0 .06 -0.77 0.50 5 1 .00 0.52 0.54 6 1 .00 0.52 T.T. 1 .00 166 Table XXV -R e l i a b i l i t y of T o t a l T e s t , Minus Item 4 Pro BELIEF Statement Item* BELIEF MEASURE Item S t a t i s t i c s Mean S.D. C o r r e l a t i o n s s.t t . t MSI Hoyt S.E. 1. (Pro) 1 2.99 1 .61 0.91 0.38 8.98 0.88 6.26 2 3.48 1 .76 0.84 0.39 3 4 3.06 1 .79 0.91 0.40 2. ( A n t i ) 1 5.21 1 .74 0.95 0.31 2.86 0.94 4.65 2 5.27 1 .69 0.94 0.30 3 4 4.98 1.71 0.92 0.28 3. ( A n t i ) 1 5.18 1 .61 0.94 0.14 3.62 0.92 4.50 2 5.51 1 .38 0.93 0.22 3 4 5.30 1 .30 0.87 0.19 4. ( A n t i ) 1 5.12 1 .52 0.94 0.31 5.21 0.91 4.82 2 5.34 1 .46 0.92 0.33 3 4 4.93 1 .43 0.85 0.26 5. (Pro) 1 2.65 1 .76 0.80 0.28 0.64 0.79 7.94 2 2.78 1 .79 0.84 0.26 3 4 2.77 1 .76 0.79 0.27 6. (Pro) 1 4.14 1 .81 0.96 0.40 3.68 0.94 4.75 2 4.17 1 .77 0.93 0.42 3 3.86 1 .84 0.93 0.43 4 167 Table XXVI - Test S t a t i s t i c s (Minus Item 4 Pro) BELIEF Measure ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124.00 603.9 4 .87 Items 17.00 2396.32 140 .96 R e s i d u a l 2108.00 554.13 2 .63 T o t a l 2249.00 8554.35 3 .80 Hoyt=0.46 Standard Error=6. 69 CORRELATIONS Statement* 1 2 3 4 5 6 T o t a l Test 1 1 .00 -0.43 -0.46 -0.20 0. 33 0 .51 0.44 2 1.00 0.41 0.22 -0. 15 -0 .35 0.32 3 1 .00 0.56 -0. 47 -0 .43 0.20 4 1 .00 -0. 42 -0 .28 0.33 5 1 . 00 0 .26 0.32 6 1 .00 0.44 T.T. 1 .00 168 Table XXVII - R e l i a b i l i t y of Pro Statements Only ATTITUDE ATTITUDE MEASURE Statement Item# Item S t a t i s t i c s MSI Hoyt S.E. Mean S.D. C o r r e l a t i o n s s . t . t . t 1. (Pro) 1 4.73 2.13 0.85 0.69 5.25 0.89 7.41 2 4.75 2.11 0.85 0.66 3 4.32 1 .87 0.79 0.64 4 4.50 2.11 0.87 0.66 5. (Pro) 1 2.94 1 .65 0.79 0.63 1 .22 0.92 5.28 2 3.03 1 .75 0.90 0.72 3 2.90 1 .58 0.91 0.71 4 2.79 1 .62 0.92 0.71 6. (Pro) 1 3.72 1 .65 0.87 0.73 0.75 0.91 5.37 2 3.54 1 .69 0.93 0.72 3 3.62 1 .61 0.83 0.64 4 3.66 1 .72 0.87 0.74 Table XXVIII - Test S t a t i s t i c s Pro Statements Only -ATTITUDE Source of v a r i a n c e ANOVA Degrees Sums of of Freedom Squares Mean Square I n d i v d u a l 124 3425.20 18.12 I tems 23 2614.80 64.81 R e s i d u a l 2852 6937.66 1 .90 T o t a l 2999 11288.97 3.71 Hoyt=0.90 Standard Error=4.58 CORRELATIONS STATEMENT # 2 3 TOTAL TEST 1 0.33 0.37 0. 77 2 0.52 0. 77 3 0. 79 169 Table XXIX - R e l i a b i l i t y of Pro Statements Only Test -BELIEF BELIEF MEASURE Statement Item# I tern S t a t i s t i c s MSI Hoyt S.E. Mean S.D. C o r r e l a t i o n s s.t t . t 1. (Pro) 1 2.98 1 .63 0.83 0.68 59.34 0.81 7.55 2 3.48 1 .76 0.81 0.71 3 3.06 1 .80 0.85 0.71 4 4.48 1 .87 0.59 0.50 5. (Pro) 1 2.65 1 .76 0.71 0.47 40.57 0.79 8.26 2 2.78 1 .79 0.80 0.54 3 2.77 1 .76 0.78 0.62 4 3.86 2.09 0.70 0.64 6. (Pro) 1 4.14 1.81 0.94 0.75 1 1 .79 0.94 4.94 2 4.17 1 .77 0.93 0.76 3 3.86 1 .84 0.90 0.75 4 4.60 1 .69 0.86 0.72 Table XXX - Test S t a t i s t i c s Pro Statements Only - BELIEF Source of v a r i a n c e ANOVA Degrees Sums of of Freedom Squares Mean Square I n d i v d u a l 124 2048.73 16.52 I terns 11 684.32 62.21 R e s i d u a l 1364 2773.02 2.03 T o t a l 1499 5506.07 3.67 Hoyt=0.88 Standard Error=4.73 CORRELATIONS STATEMENT # 1 2 3 TOTAL TEST 1 1 .00 0.40 0.51 0 .80 2 1.00 0.34 0 .73 3 1 .00 0 .81 170 Table XXXI - R e l i a b i l i t y of A n t i Statements Only Test -ATTITUDE ATTITUDE MEASURE Statement Item* I tern S t a t i s t i c s MSI Hoyt S .E. Mean S.D. C o r r e l a t i o n s s . t . t . t 2. ( A n t i ) 1 4.89 1 .77 0.67 0.49 16. 39 0.79 6 .85 2 5.70 1 .53 0.85 0.64 2 5.42 1 .42 0.73 0.59 3 5.61 1 .44 0.77 0.67 3. ( A n t i ) 1 3.79 1 .82 0.58 0.51 53. 45 0.74 7 .98 2 4.94 1.71 0.77 0.73 3 5.06 1 .59 0.71 0.64 4 5.23 1 .60 0.76 0.68 4. (A n t i ) 1 3.89 1 .67 0.44 0.35 74. 15 0.68 7 .84 2 5.29 1 .66 0.77 0.65 3 5.25 1 .52 0.70 0.59 4 5.63 1 .42 0.77 0.65 Table XXXII - Test S t a t i s t i c s ( A n t i statements only) ATTITUDE ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124 1347.23 10.87 I terns 11 537.74 48.89 R e s i d u a l 1364 2463.94 1.81 T o t a l 1499 4349.08 2.90 Hoyt=0.83 Standard Error=4.46 CORRELATIONS STATEMENT # 1 2 3 TOTAL TEST 1 1.00 0.46 0.33 0.75 2 1.00 0.56 0.85 3 1 .00 0.78 171 Table XXXIII - R e l i a b i l i t y of A n t i Statements Only Test -BELIEF BELIEF MEASURE Statement Item# Item S t a t i s t i c s MSI Hoyt S.E. Mean S.D. C o r r e l a t i o n s 2. ( A n t i ) 1 5. 21 1 .74 0. 94 0. 72 10.53 0.93 4.28 2 5. 27 1 .69 0 94 0. 68 2 4 98 1 .71 0 .89 0 .67 3 5 .68 1 .32 0 .80 0 .61 . 3. (Ant i ) 1 5.18 1 .61 0.91 0.79 10.86 0. 87 5.25 2 5.51 1 .38 0.89 0.76 3 5.30 1 .30 0.86 0.72 4 5.85 1 .19 0.62 0.51 4. (Anti ) 1 5.12 1 .52 0.91 0.73 15.95 0. 91 4.65 2 5.34 1 .46 0.91 0.71 3 4.93 1 .43 0.84 0.63 4 5.76 1 . 1 1 0.80 0.54 Table XXXIV - Test S t a t i s t i c s ( A n t i Statements only) BELIEF Source of v a r i a n c e ANOVA Degrees of Freedom Sums of Squares Mean Square I n d i v d u a l I tems R e s i d u a l T o t a l 124 1 1 1 364 1 499 1448.77 121.91 1765.52 3336.20 1 1 .68 1 1 .08 1 .29 2.23 Hoyt=0.89 Standard Error=3.77 CORRELATIONS STATEMENT #1 2 3 TOTAL TEST 1 1.00 0.39 0.20 0.74 2 1.00 0.57 0.83 3 1.00 0.74 172 Table XXXV - R e l i a b i l i t y of Pro Statements Only Test -BELIEF (Minus Item4) Statement Item# BELIEF MEASURE (MINUS ITEM Item S t a t i s t i c s Mean S.D. C o r r e l a t i o n s s . t . t . t . 4) MSI Hoyt S.E. 1. (Pro) 1 2.94 1 .59 0.90 0.71 10.33 0.87 6.33 2 3.48 1 .76 0.83 0.70 3 3.03 1 .77 0.91 0.75 5. (Pro) 4 1 2.65 1 .76 0.80 0.49 0.69 0.79 7.93 2 2.78 1 .79 0.84 0.57 3 * 2.77 1 .76 0.79 0.63 6. (Pro) 4 1 4.12 1 .81 0.96 0.75 3.68 0.94 4.75 2 4.15 1 .77 0.93 0.75 3 4 3.84 1 .84 0.93 0.77 Table XXXVI - Test S t a t i s t i c s (Pro Statements Only) BELIEF ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124.00 Items 8.00 R e s i d u a l 992.00 T o t a l 1124.00 1602.04 12.92 361.84 45.23 1865.71 1.88 3829.59 3.41 Hoyt=0.85 Standard Error=3. 88 CORRELATIONS STATEMENT #1 2 3 TOTAL TEST 1 1.00 0.33 2 1 .00 3 0.51 0.81 0.25 0.67 1.00 1.00 173 Table XXXVII -R e l i a b i l i t y of A n t i Statements Only Test ATTITUDE Statement ATTITUDE MEASURE (MINUS ITEM Item# Item S t a t i s t i c s Mean S.D. C o r r e l a t i o n s s . t . t . t . 1) MSI Hoyt S. E. 2. ( A n t i ) 1 2. 56 0. 82 6. 16 2 5. 70 1 .53 0. 84 0. 63 2 5. 42 1 .42 0. 83 0. 64 3 5. 61 1 .44 0. 85 0. 69 3. ( A n t i ) 1 2. 75 0 79 7. 38 2 4. 94 1 .71 0 .79 0 .73 3 5. 06 1 .59 0 .83 0 .72 4 5 23 1 .60 0 .81 0 .71 4. (A n t i ) 1 5 .57 0 .80 6. 76 2 5 .29 1 .66 0 .79 0 .63 3 5 .25 1 .52 0 .82 0 .69 4 5 .63 1 .42 0 .87 0 .73 Table XXXVIII - Test S t a t i s t i c s (Anti Statements Only) Minus Item 1 ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 124 1249.03 10.07 Items 8 68.93 8.62 R e s i d u a l 992 1420.86 1 .43 T o t a l 1124 2738.81 2.44 Hoyt=0.86 Standard Error=3.39 CORRELATIONS STATEMENT # 1 2 3 TOTAL TEST 1 1.00 0.50 0.37 0.76 2 1 .00 0.57 0.86 3 1 .00 0.80 174 Table XXXIX -R e l i a b i l i t y of A n t i Statements Only Test BELIEF BELIEF MEASURE (n=116) Statement Item# Item S t a t i s t i c s MSI Hoyt S.E. Mean S.D. C o r r e l a t i o n s s. t t . t 2. ( A n t i ) 1 5.47 1 .50 0.90 0.58 7.96 0.90 4.82 2 5.52 1 .45 0.92 0.56 2 5.22 1 .54 0.86 0.55 3 5.85 1 .44 0.75 0.46 3. (A n t i ) 1 5.34 1 .50 0.89 0.78 7.62 0.86 5 .09 2 5.66 1 .25 0.88 0.73 3 5.40 1 .24 0.85 0.72 4 5.90 1 .19 0.62 0.55 4. (A n t i ) 1 5.28 1 .39 0.91 0.69 1 1 .93 0.91 4 .21 2 5.49 1 .35 0.92 0.66 3 5.03 1 .34 0.84 0.64 4 5.79 1 .12 0.84 0.61 Table XL - Test S t a t i s t i c s ( A n t i Statements Only) -BELIEF ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v i d u a l 115 974.15 8.47 Items 11 89.98 8.18 Re s i d u a l 1265 1511.86 1.20 T o t a l 1391 2576.00 1.85 Hoyt=0.86 Standard E r r o r =3.63 CORRELATIONS Statement #1 2 3 T o t a l Test 1 1.00 0.25 0.02 0.61 2 1.00 0.60 0.83 3 1.00 0.73 175 Table XLI - R e l i a b i l i t y of A n t i Statements Only Test -ATTITUDE ATTITUDE MEASURE (n=116) Statement Item# Item S t a t i s t i c s MSI Hoyt S .E • Mean S.D. C o r r e l a t i o n s s. t t . t 2. ( A n t i ) 1 4.86 1 .80 0.66 0.48 16.15 0.79 6. 90 2 5.69 1 .56 0.85 0.64 2 5.46 1 .41 0.74 0.61 3 5.60 1 .43 0.78 0.68 3. ( A n t i ) 1 3.78 1 .86 0.60 0.53 6.67 0.75 7. 99 2 4.89 1 .74 0.78 0.74 3 5.08 1 .63 0.71 0.63 4 5.24 1 .60 0.77 0.69 4. ( A n t i ) 1 3.84 1 .69 0.44 0.35 75.46 0.69 7. 93 2 5.28 1 .70 0.78 0.64 3 5.30 1 .56 0.72 0.61 4 5.67 1 .43 0.77 0.66 Table XLII - Test S t a t i s t i c s - ATTITUDE Source of v a r i a n c e ANOVA Degrees Sums of of Freedom Squares Mean Square I n d i v d u a l I tems R e s i d u a l T o t a l 115 1308.40 11 528.60 1265 2328.41 1391 4165.41 1 1 .38 48.05 1 .84 2.99 Hoyt=0.84 Standard Error=4.50 CORRELATIONS STATEMENT # 1 1 2 3 1 2 3 TOTAL TEST .00 0.46 0.34 0.76 1.00 0.55 0.85 1.00 0.78 176 Table XLIII - R e l i a b i l i t y of A n t i Statements Only Test -ATTITUDE Statement Item# ATTITUDE MEASURE (MINUS ITEM 1, n=116) Item S t a t i s t i c s MSI Hoyt S.E. Mean S.D. C o r r e l a t i o n s s . t . t . t . 2. ( A n t i ) 1 1 .61 0 .83 6.07 2 5.69 1 .56 0.84 0.63 2 5.46 1.41 0.84 0.65 3 5.60 1 .43 0.86 0.70 3. ( A n t i ) 1 3.63 0 .79 7.42 2 4.89 1 .74 0.80 0.74 3 5.08 1 .63 0.83 0.72 4 5.24 1 .60 0.81 0.71 4. ( A n t i ) 1 5.71 81 6 80 2 5.28 1 .70 0.79 0.62 3 5.30 1 .56 0.83 0.71 4 5.67 1 .43 0.87 0.74 Table XLIV - Test S t a t i s t i c s ( A n t i Statements Only) -ATTITUDE ANOVA Source of v a r i a n c e Degrees Sums of Mean Square of Freedom Squares I n d i v d u a l 1 1 5 1206.78 10.49 Items 8 69.82 8.73 R e s i d u a l 920 1 330.85 1 .45 T o t a l 1391 2607.45 2.50 Hoyt=0.86 Standard Error=3. 40 CORRELATIONS STATEMENT # 1 2 3 TOTAL TEST 1 1.00 0.50 0.38 0.76 2 1 .00 0.57 0.86 3 1 .00 0.80 177 Table XLV - R e l i a b l i t y of Measure For BELIEF IN MESSAGE BELIEF IN MESSAGE Item S t a t i s t i c s C o r r e l a t i o n s Item # Mean S.D. s. t . t . t . 1 4.20 1 .85 0.94 0.95 2 4.30 1 .82 0.94 0.95 3 4.61 1 .68 0.93 0.94 4 4.13 1 .67 0.95 0.96 Table XLVI - T o t a l Test S t a t i s t i c s ANOVA Source of Va r i a n c e Degrees Sums of Squares of Freedom Mean Squares I n d i v i d u a l 124 1375.20 1 1 .09 I tern 3 16.76 5 .59 R e s i d u a l 372 154.99 0 .42 T o t a l 499 1546.95 3 .10 Hoyt=0.96 Standard Error=3. 99 IV. MULTIPLE REGRESSION ANALYSIS Based on the r e l i a b i l i t y assessment of the survey, m u l t i p l e r e g r e s s i o n a n a l y s i s was conducted on the data from the a n t i food a d d i t i v e statements only, with n=116 and minus item 1 on the a t t i t u d e measure.. R e s u l t s were d i s a p p o i n t i n g , with a low c o e f f i c i e n t of de t e r m i n a t i o n (.1368), which was not co n s i d e r e d to account f o r a reasonable amount of the v a r i a n c e i n b e l i e f i n the message. M u l t i p l e Regression was then conducted on the p o s i t i v e statements, with n=1l6, and a reasonable c o e f f i c i e n t of det e r m i n a t i o n was obtained (.4814). Because of the smal l d i f f e r e n c e i n r e l i a b i l i t y r a t i n g s , another M.R. was run on the pro statements, n=l25, minus item 4 on the b e l i e f measure, and again a good R2 of .4809 was obt a i n e d . In an attempt to gain the best p o s s i b l e R2, item 4 on the 178 B e l i e f measure was r e i n c l u d e d i n the data . An R2 of .4923 was the best r e s u l t o b t a i n e d . M u l t i p l e r e g r e s s i o n was performed on other v a r i a t i o n s of the data as shown i n t a b l e XX. The q u e s t i o n now presented i t s e l f as to which data should be used f o r the M.R. a n a l y s i s . F i r s t , i t was not r e a l l y p o s s i b l e to j u s t i f y u s ing n=116 f o r the p o s i t i v e statements. The 9 responses were removed on the b a s i s of d i s b e l i e f i n the negative statements. T h e r e f o r e , i t was c o n s i d e r e d best to use the n=l25 data. Second, should item 4 on the b e l i e f measure be r e t a i n e d or e l i m i n a t e d ? The f o l l o w i n g t a b l e summarizes the data on which the f i n a l d e c i s i o n was based. Table XLVII - C r i t e r i a f o r S e l e c t i n g Data With Item 4 B e l i e f Measure Minus Item 4 B e l i e f Measure R e l i a b i l i t y : Hoyt=.0.88 Hoyt=0.85 Standard Error= 4.73 Standard Error= 3.88 ANOVA Mean Square Mean Square I n d i v i d u a l 16.29 12.92 Items 62.18 45.23 R e s i d u a l 2.04 1 .88 T o t a l 3.66 3.41 Coeff i c i e n t of Determination 0.4923 0.4809 Based on the above data, i t was f e l t the removal of item 4 d i d not r e s u l t i n a great d e a l of improvement i n the s t a t i s t i c s , while i n c l u s i o n of item 4 o f f e r e d a s l i g h t l y h i g h e r c o e f f i c i e n t of d e t e r m i n a t i o n . 179 Table XLVIII -Summary of M u l t i p l e Regression Analyses on V a r i o u s Data TEST R2 A F P.V.I X4(Bel) * X5(Att) 1. Anti,n=116 13. 78. 1 1 2. 12 12.56% 0.49% 2. Pro, n=116 48. 14 5. 48 12. 41 42.81 2.25 3. Pro, n=116,minus4Bel 4. Pro, n=125 49. 23 0. 53 14. 06 44. 14 2.17 5. Pro, n=125,minus4Bel 48. 09 0. 72 13. 43 40.72 4.28 6. Anti,n=125 17. 46 76. 86 3. 04 16.20 0.30 7. Anti,n=125,minus1Att 17. 12 76. 62 2. 99 16.20 0.35 8. Pro+Anti,n=125 , (Pro-4Bel+ A n t i - 1 A t t ) 2 5 . 20 -4. 24 4. 89 4.71 18.49 *P.V.I. = P o r p o r t i o n of V a r i a n c e Increment V. MEAN SCORES OF RESPONSES The f o l l o w i n g t a b l e s and graphs represent the frequency of responses f o r the measurement instrument that c o n s i s t e d of negative statements o n l y . I t i s of i n t e r e s t to note that respondents q u i t e s t r o n g l y b e l i e v e d the negative statements about food a d d i t i v e s (75.2% scored g r e a t e r than 4.51). Although the statements are not s c i e n t i f i c a l l y t r u e , they do represent popular sentiments about the supposed r i s k to h e a l t h from food a d d i t i v e s . T h i s may be support f o r the idea that a t t i t u d e s toward food a d d i t i v e s are due to t h e i r s t e r e o t y p e d image. The n e g a t i v e statements were not used because they f a i l e d to produce a s i g n i f i c a n t amount of v a r i a n c e when the m u l t i p l e r e g r e s s i o n a n a l y s i s was conducted. T h i s may have been due to the f a c t t h a t both f o r the a t t i t u d e v a r i a b l e and the c o v a r i a t e , the s c o r e s were not widely d i s t r i b u t e d over the t o t a l range of p o s s i b l e responses. The r e s u l t l i n g l a c k of v a r i a b i l i t y may have produced the poor c o e f f i c e n t of d e t e r m i n a t i o n . In a d d i t i o n , as can be seen i n F i g u r e 8 , the responses to the a t t i u d e measure were a l s o not widely d i s t r i b u t e d , with 71% 180 of respondents s c o r i n g g r e a t e r than 4.51. T h i s would normally i n d i c a t e a p o s i t i v e a t t i t u d e . However, there appears to be a problem with the s c a l e s . I f a person i s a n t i - f o o d a d d i t i v e , t h e o r e t i c a l l y he or she should be f a v o u r a b l e about the a n i t - f o o d a d d i t i v e statements and mark the f a v o u r a b l e end of the s c a l e and hence r e c e i v e a low s c o r e . ( S c o r i n g of s c a l e s i s reversed f o r the negative statements). However, i n t h i s case, c e r t a i n of the a d j e c t i v e s used i n the a t t i t u d e s c a l e s seem to act d e n n o t a t i v e l y . In p a r t i c u l a r , the words s i c k , harmful, bad and f o o l i s h are c l e a r l y a s s o c i a t e d with food a d d i t i v e s by some people and thus the unfavourable end of the s c a l e i s marked and respondents r e c e i v e a high score, even i f they have a negative a t t i t u d e toward food a d d i t i v e s . In the t h e o r e t i c a l response, the s c a l e s work c o n n o t a t i v e l y by i l l i c i t n g an a f f e c t i v e response to the sentiments expressed i n the tatement. Table XLIX - Response Frequency of Mean BELIEF Scores -A n t i Statements BELIEF IN STATEMENTS Statement#2 Statement#3 Statement#4 Average Score Freq. % Cum.% F r e q . % Cum.% F r e q . % Cum.% Freq. % Cum.: 1 3 2.4 2.4 - - 1 0.8 0.8 — — — 2 6 4.8 7.2 1 0.8 0.8 2 1.6 2.4 - - — 3 10 8.0 15.2 10 8.0 8.8 8 6.4 8.8 6 4.8 4.8 4 15 12.0 27.2 20 16.0 24.8 23 18.4 27.2 25 20.0 24.8 5 2 22.4 29.6 28 22.4 47.2 32 25.6 52.8 36 28.8 53.6 6 39 31.2 80.8 44 35.2 82.4 39 31.2 84.0 45 36.0 89.6 7 9 1.2 100.0 22 17.6 100 20 16.0 100 13 10.4 100 Mean Score 5.176 5. 360 5.240 5.272 181 F i g u r e 7 - Histogram of Mean BELIEF scores - A n t i Statements Code 1 . (0-1.5) 2. (1.5102.5) 3. (2.51-3.5) (3.51-4.5) 5. (4.51-5.5) 6. (5.51-6.5) 7. (6.51-7.5) * * * * * * ( 5 ) ************************* (25) ************************************ (36) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ( 4 5 ) * * * * * * * * * * * * * ( 1 3 ) I, 0 10 Frequency I I I... i I 20 30 40 50 (Number i n Brackets=frequency) 182 Table L - Response Frequency of Mean ATTITUDE scores -A n t i Statements Statement #2 Statement #3 Statement #4 Average Code Fre q . % Cum.% Fre q . % Cum.% F r e q . % Cum.% Fre q . % Cum.% 1 1 0.8 0.8 3 2.4 2.4 2 1 .6 1.6 1 0.8 0.8 2 3 2.4 3.2 6 4.8 7.2 2 1.6 3.2 2 1.6 2.4 3 4 3.2 6.4 3 2.4 9.6 1 0.8 4.0 2 1.6 4.0 4 22 17.6 24.0 48 38.4 48.0 40 32.0 36.0 30 24.0 28.0 5 40 32.0 56.0 36 28.8 76.8 44 35.2 71.2 55 44.0 72.0 6 32 25.6 81 .6 18 14.4 91 .2 25 20.0 91 .2 29 23.2 95.2 7 23 18.4 100 1 1 8.8 100 1 1 8.8 100 6 4.8 100 Mean Score 5.280 4.648 4.928 4.976 F i g u r e 8 - Histogram of Mean ATTITUDE Scores - A n t i Statements Code I 1 . I* (1) (0-1.5) I I 2. I * * (2) (1.51-2.5)1 I 3. I * * (2) (2.51-3.5)1 I 4^  j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (30) (3.51-4.5)1 I 5 j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (4.51-5.5)1 (55) I 6 # j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (29) (5.51-4.5)1 I 7. I * * * * * * (6) (4.51-5.5)1 I I I I I I I 0 10 20 30 40 50 Frequency 183 BIBLIOGRAPHY 1. Ajzen, I . , and F i s h b e i n , M.1980. Understanding A t t i t u d e and P r e d i c t i n g S o c i a l Behavior. P r e n t i c e H a l l Inc., Englewood C l i f f s , New Jersey,pp2l8-228. 2. Anderson, K. and Clevenger, T. Jr.1963. A Summary of Experimental Research i n Ethos. Speech Monographs 30:2(59-78). 3. Anderson, M.A. and S t a n d a l , B.R. 1975. N u t r i t i o n a l Knowledge of H e a l t h Food Users i n Oahu, Hawaii. J o u r n a l of the American D i e t e t i c A s s o c i a t i o n . 68:116. 4. Annonymous. 1973. Food Fadism. 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