"Education, Faculty of"@en . "Educational and Counselling Psychology, and Special Education (ECPS), Department of"@en . "DSpace"@en . "UBCV"@en . "Kuppers, Reiner"@en . "2010-06-03T19:15:06Z"@en . "1985"@en . "Master of Arts - MA"@en . "University of British Columbia"@en . "The purpose of this study was to compare the practice effects of \"normal\" students on the WISC-R Coding subtest to those of \"learning disabled\" students, to see if Coding can be used as a measure of \"learning potential.\" In addition, data from the WISC-R Coding subtest were compared to subjects' scores from the four subtests of the British Columbia Quick Individual Educational Test (B.C.Q.U.I.E.T.). The WISC-R Coding subtest was administered to 38 students from two school districts, one urban and one rural; it was readministered approximately 24 hours later. Seventeen of the students were classified as \"learning disabled\" and came from regional learning centers in each district. Twenty one students selected from elementary schools in the two districts were classified as \"normal.\" Analysis of the data showed that the students could be pooled into two groups, one labeled \"normal\" and one \"learning disabled.\" Further analysis found significant differences between the pre-and posttest Coding scores for the normal group but not for the learning disabled group. There was also a significant difference between the two groups on both their pre-and posttest Coding scores. Significant correlations were found between all four of the B.C.Q.U.I.E.T. subtest and posttest Coding scores for normal subjects. The learning disabled group's scores correlated significantly with the Coding subtest. For the normal group no significant correlations were found between pre-and posttest Coding scores; however these scores were correlated significantly for the learning disabled group. A multivariate discriminant analysis\r\nfound the two groups could be clearly separated by using a combination of all four B.C.Q.U.I.E.T. subtests and the pre-and posttest Coding scores.\r\nResults indicated that students classified as \"normal\" showed significantly greater practice effects on the WISC-R Coding subtest than students classified as \"learning disabled\". Furthermore these two groups could be identified clearly using a discriminant analysis with a combination of all four subtests of the B.C.Q.U.I.E.T. and pre-and posttest Coding scores. It would seem that there is merit in pursuing the use of the WISC-R Coding test-retest scores to screen for learning disabilities, especially in combination with B.C.Q.U.I.E.T. subtest scores. Implications were\r\ndiscussed."@en . "https://circle.library.ubc.ca/rest/handle/2429/25434?expand=metadata"@en . "AN INVESTIGATION OF THE WISC-R CODING SUBTEST AS A MEASURE OF LEARNING POTENTIAL By REINER KUPPERS B.A., W a l l a W a l l a C o l l e g e , 1974 THESIS SUBMITTED IN PARTIAL FULFILLMENT THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS i n THE FACULTY OF GRADUATE STUDIES De p a r t m e n t o f EDUCATIONAL PSYCHOLOGY AND SPECIAL EDUCATION We a c c e p t t h i s t h e s i s a s c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA March 1985 (c) R e i n e r K u p p e r s , 1985 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 o f B r i t i s h Columbia, I agree t h a t 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 t h a t p e r m i s s i o n f o r e x t e n s i v e copying o f 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 t h a t 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 g a i n 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 . The U n i v e r s i t y of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 )E-6 (3/81) . i i ABSTRACT The p u r p o s e o f t h i s s t u d y was t o c o m p a r e t h e p r a c t i c e e f f e c t s o f \" n o r m a l \" s t u d e n t s o n t h e WISC-R C o d i n g s u b t e s t t o t h o s e o f \" l e a r n i n g d i s a b l e d \" s t u d e n t s , t o s e e i f C o d i n g c a n be u s e d a s a m e a s u r e o f \" l e a r n i n g p o t e n t i a l . \" In a d d i t i o n , d a t a f r o m t h e WISC-R C o d i n g s u b t e s t were c o m p a r e d t o s u b j e c t s ' s c o r e s f r o m t h e f o u r s u b t e s t s o f t h e B r i t i s h C o l u m b i a Q u i c k I n d i v i d u a l E d u c a t i o n a l T e s t ( B . C . Q . U . I . E . T . ) . The WISC-R C o d i n g s u b t e s t was a d m i n i s t e r e d t o 38 s t u d e n t s f r o m two s c h o o l d i s t r i c t s , one u r b a n and one r u r a l ; i t was r e a d m i n i s t e r e d a p p r o x i m a t e l y 24 h o u r s l a t e r . S e v e n t e e n o f t h e s t u d e n t s were c l a s s i f i e d as \" l e a r n i n g d i s a b l e d \" and came f r o m r e g i o n a l l e a r n i n g c e n t e r s i n e a c h d i s t r i c t . T w e n t y one s t u d e n t s s e l e c t e d f r o m e l e m e n t a r y s c h o o l s i n t h e two d i s t r i c t s were c l a s s i f i e d as \" n o r m a l . \" A n a l y s i s o f t h e d a t a showed t h a t t h e s t u d e n t s c o u l d be p o o l e d i n t o two g r o u p s , one l a b e l e d \" n o r m a l \" and one \" l e a r n i n g d i s a b l e d . \" F u r t h e r a n a l y s i s f o u n d s i g n i f i c a n t d i f f e r e n c e s b e t w e e n t h e p r e - a n d p o s t t e s t C o d i n g s c o r e s f o r t h e n o r m a l g r o u p b u t n o t f o r t h e l e a r n i n g d i s a b l e d g r o u p . T h e r e was a l s o a s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e two g r o u p s o n b o t h t h e i r p r e - a n d p o s t t e s t C o d i n g s c o r e s . S i g n i f i c a n t c o r r e l a t i o n s were f o u n d b e t w e e n a l l f o u r o f t h e B . C . Q . U . I . E . T . s u b t e s t and p o s t t e s t C o d i n g s c o r e s f o r n o r m a l s u b j e c t s . The l e a r n i n g d i s a b l e d g r o u p ' s s c o r e s c o r r e l a t e d s i g n i f i c a n t l y w i t h t h e C o d i n g s u b t e s t . . i i i F o r t h e n o r m a l g r o u p no s i g n i f i c a n t c o r r e l a t i o n s were f o u n d b e t w e e n p r e - a n d p o s t t e s t C o d i n g s c o r e s ; h o w e v e r t h e s e s c o r e s were c o r r e l a t e d s i g n i f i c a n t l y f o r t h e l e a r n i n g d i s a b l e d g r o u p . A m u l t i v a r i a t e d i s c r i m i n a n t a n a l y s i s f o u n d t h e two g r o u p s c o u l d be c l e a r l y s e p a r a t e d by u s i n g a c o m b i n a t i o n o f a l l f o u r B . C . Q . U . I . E . T . s u b t e s t s and t h e p r e - a n d p o s t t e s t C o d i n g s c o r e s . R e s u l t s i n d i c a t e d t h a t s t u d e n t s c l a s s i f i e d a s \" n o r m a l \" showed s i g n i f i c a n t l y g r e a t e r p r a c t i c e e f f e c t s on t h e WISC-R C o d i n g s u b t e s t t h a n s t u d e n t s c l a s s i f i e d a s \" l e a r n i n g d i s a b l e d \" . F u r t h e r m o r e t h e s e two g r o u p s c o u l d be i d e n t i f i e d c l e a r l y u s i n g a d i s c r i m i n a n t a n a l y s i s w i t h a c o m b i n a t i o n o f a l l f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . and p r e - a n d p o s t t e s t C o d i n g s c o r e s . I t w o u l d seem t h a t t h e r e i s m e r i t i n p u r s u i n g t h e u s e o f t h e WISC-R C o d i n g t e s t - r e t e s t s c o r e s t o s c r e e n f o r l e a r n i n g d i s a b i l i t i e s , e s p e c i a l l y i n c o m b i n a t i o n w i t h B . C . Q . U . I . E . T . s u b t e s t s c o r e s . I m p l i c a t i o n s were d i s c u s s e d . . i v TABLE OF CONTENTS ABSTRACT i i TABLE OF CONTENTS ' i v L I S T OF TABLES .' v i L I S T OF FIGURES v i i ACKNOWLEDGEMENTS v i i i CHAPTER I : The P r o b l e m 1 I n t r o d u c t i o n 1 C o d i n g and l e a r n i n g d i s a b i l i t i e s 2 T e s t - r e t e s t method w i t h C o d i n g s c o r e s 3 Summary ' 4 P u r p o s e o f t h e s t u d y 4 R e s e a r c h q u e s t i o n s 6 H y p o t h e s e s 7 D e f i n i t i o n o f t e r m s 8 Summary 8 CHAPTER I I : Review o f t h e L i t e r a t u r e 10 P r o b l e m s o f a s s e s s m e n t 10 W e c h s l e r I n t e l l i g e n c e S c a l e and l e a r n i n g d i s a b l e d p o p u l a t i o n s 12 P e r f o r m a n c e o f d i s a b l e d r e a d e r s on WISC s u b t e s t s 12 P e r f o r m a n c e o f s u b j e c t s w i t h l e a r n i n g p r o b l e m s on t h e WISC-R 13 F a c t o r s t r u c t u r e and t e s t s c a t t e r o f W e c h s l e r s c a l e s ... 15 C o d i n g 17 V a l i d i t y o f u s i n g C o d i n g as a measure o f l e a r n i n g a b i l i t y 20 T e s t - r e t e s t as a measure o f l e a r n i n g d i s a b i l i t y . 22 T e s t - r e t e s t s t u d i e s o f t h e W e c h s l e r s c a l e s 28 Summary 3 2 CHAPTER I I I : Method 3 5 S e l e c t i o n o f s u b j e c t s 35 Normal g r o u p s 3 6 D i s a b l e d g r o u p s 36 I n s t r u m e n t s 36 C o d i n g 37 B.C.Q.U.I.E.T 38 P r o c e d u r e 39 Normal g r o u p 3 9 L e a r n i n g d i s a b l e d g r o u p 39 A n a l y s i s o f t h e d a t a 40 H y p o t h e s e s 1-3 40 H y p o t h e s i s 4 '. 40 H y p o t h e s i s 5 .. 41 Summary 4 2 CHAPTER IV : R e s u l t s 43 A n a l y s i s o f t h e d a t a 43 H y p o t h e s i s one 46 H y p o t h e s i s two 48 H y p o t h e s i s t h r e e 50 H y p o t h e s i s f o u r 52 H y p o t h e s i s f i v e 55 Summary 5 7 CHAPTER V : D i s c u s s i o n and I m p l i c a t i o n s 58 P r a c t i c e e f f e c t on WISC-R C o d i n g s u b t e s t 58 WISC-R C o d i n g and B.C.Q.U.I.E.T. c o r r e l a t i o n s 61 M u l t i v a r i a t e d i s c r i m i n a n t a n a l y s i s 63 L i m i t a t i o n s o f t h e s t u d y 64 D i r e c t i o n s f o r f u t u r e r e s e a r c h 65 BIBLIOGRAPHY 67 APPENDIX 71 . v i L I S T OF TABLES T a b l e 1 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r f o u r B.C.Q.U.I.E.T s u b t e s t s ( n o r m a l g r o u p s : C - C h i l l i w a c k ; K-Kamloops) 4 5 T a b l e 2 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r f o u r B.C.Q.U.I.E.T. s u b t e s t s ( l e a r n i n g d i s a b l e d g r o u p s : C - C h i l l i w a c k ; K-Kamloops) 45 T a b l e 3 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r n o r m a l s u b j e c t s ( t e s t - r e t e s t : WISC-R C o d i n g s u b t e s t ) 47 T a b l e 4 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r l e a r n i n g d i s a b l e d s u b j e c t s ( t e s t - r e t e s t : WISC-R C o d i n g s u b t e s t ) 49 T a b l e 5 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s between n o r m a l and l e a r n i n g d i s a b l e d s u b j e c t s (WISC-R C o d i n g s u b t e s t ) 51 T a b l e 6 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s between n o r m a l and l e a r n i n g d i s a b l e d s u b j e c t s ( R e t e s t : WISC-R C o d i n g s u b t e s t ) 51 T a b l e 7 P e a r s o n r c o r r e l a t i o n c o e f f i c i e n t s b etween WISC-R C o d i n g and B.C.Q.U.I.E.T. s u b t e s t s c o r e s ( N o r m a I s - u p p e r h a l f , L e a r n i n g d i s a b l e d - l o w e r ) 54 T a b l e 8 P e a r s o n r c o r r e l a t i o n c o e f f i c i e n t s b etween WISC-R C o d i n g and B.C.Q.U.I.E.T. s u b t e s t s c o r e s ( N o r m a l s and l e a r n i n g d i s a b l e d s c o r e s p o o l e d ) 54 T a b l e 9 D i s c r i m i n a n t a n a l y s i s 56 . v i i L I S T OF F IGURES F i g u r e 1 P h a s e s o f L e a r n i n g F i g u r e 2 Some S e l e c t e d Common L e a r n i n g D i f f i c u l t i e s o f L e a r n i n g D i s a b l e d S t u d e n t s A f f e c t i n g M a t h P e r f o r m a n c e -21 21 . v i i i ACKNOWLEDGEMENTS I would l i k e to thank the members of my Thesis committee, Dr. E. Goetz, and Dr. H. R a t z l a f f for having guided me through the research with so much patience, kindness and understanding. I t has been a p r i v i l e g e f o r me to work with them. I would also l i k e to thank the students and teachers of the regional learning centers and elementary schools i n the Chilliwack and Kamloops School D i s t r i c t s who took part i n the study. Their willingness to p a r t i c i p a t e at a busy time of year was greatly appreciated. F i n a l l y I would l i k e to thank my family for t h e i r encouragement and help, e s p e c i a l l y my wife Eli z a b e t h f o r her patience and constant support and the many hours spent i n typing d r a f t s for me. . 1 CHAPTER I The P r o b l e m I n t r o d u c t i o n O n e o f t h e c h a l l e n g e s f a c i n g e d u c a t o r s i s t h a t o f d i s c o v e r i n g a c h i l d ' s l e a r n i n g p o t e n t i a l o r a b i l i t y . T h i s may be o f s p e c i a l i m p o r t a n c e i n t h e d i a g n o s i s a n d r e m e d i a t i o n o f t h e l e a r n i n g d i s a b l e d c h i l d w h e r e t h e r e c a n b e c o n f l i c t i n g i d e a s a b o u t t h e e t i o l o g y o f t h e d i s a b i l i t y . F o r e x a m p l e , a c h i l d may have a l e a r n i n g d i s a b i l i t y w h i c h m a n i f e s t s i t s e l f i n a n i n a b i l i t y t o p e r f o r m a t g r a d e l e v e l i n a r i t h m e t i c . E d u c a t o r s and p a r e n t s may d i s a g r e e o v e r w h e t h e r t h i s i s b e c a u s e t h e c h i l d l a c k s m o t i v a t i o n i n t h a t s u b j e c t , h a s l e a r n e d t o d i s l i k e i t and so doe s n o t p e r f o r m , o r , p e r h a p s , has an o r g a n i c p r o b l e m . I f t h e r e were a way t o e s t i m a t e t h e c h i l d ' s p o t e n t i a l f o r a c a d e m i c l e a r n i n g , q u i c k l y a n d r e l i a b l y , t h e n p e r h a p s a n e f f e c t i v e i n s t r u c t i o n a l method c o u l d be d e v e l o p e d . P r e s e n t l y , a c h i l d ' s l e a r n i n g p o t e n t i a l i s m e a s u r e d by two k i n d s o f t e s t s , a c h i e v e m e n t a n d IQ t e s t s . A c c o r d i n g t o Ross ( 1 97 7 ) h o w e v e r , b o t h o f t h e s e m e a s u r e w h a t t h e c h i l d h a s l e a r n e d i n t h e p a s t , n o t w h a t he c o u l d p e r h a p s l e a r n i n t h e f u t u r e . One t e s t , w h i c h may h a v e t h e a b i l i t y t o m e a s u r e a c h i l d ' s p o t e n t i a l o r l e a r n i n g a b i l i t y i s t h e C o d i n g s u b t e s t o f t h e WISC-R ( D e r n e r e t a l . , 1 9 5 0 ; R o s s , 1977; R o y e r , 1 9 7 1 ) . T h i s i s a t i m e d t e s t w h i c h r e q u i r e s a s u b j e c t t o m a t c h e a c h o f a g r o u p o f numbers w i t h i t s a p p r o p r i a t e s y m b o l . I t i s s i m i l a r t o p a i r e d - a s s o c i a t e l e a r n i n g t a s k s w h i c h a c c o r d i n g t o some r e s e a r c h e r s , measure l e a r n i n g p o t e n t i a l ( K r a t o c h w i l l , 1 9 7 7 ) . . 2 Two k i n d s o f r e s e a r c h o n t h e C o d i n g t e s t i n d i c a t e i t s p o s s i b l e e f f e c t i v e n e s s a s a m e a s u r e o f l e a r n i n g a b i l i t y o r p o t e n t i a l . F i r s t , some r e s e a r c h e r s h a v e e s t a b l i s h e d t h a t C o d i n g s c o r e s f o r l e a r n i n g d i s a b l e d a n d r e a d i n g d i s a b l e d c h i l d r e n d i f f e r s i g n i f i c a n t l y f r o m t h e same s c o r e s f o r c h i l d r e n o f n o r m a l l e a r n i n g a b i l i t y . S e c o n d l y t e s t - r e t e s t s t u d i e s o f t h e WISC-R i n c l u d i n g t h e C o d i n g s u b t e s t i n d i c a t e a l a r g e p r a c t i c e e f f e c t f o r n o r m a l c h i l d r e n a n d a v e r y s m a l l one f o r t h e l e a r n i n g d i s a b l e d . C o d i n g a n d L e a r n i n g D i s a b i l i t i e s . Some s t u d i e s o n t h e WISC-R h a v e l e d r e s e a r c h e r s t o s u g g e s t t h a t t h e C o d i n g s u b t e s t may be o f s i n g u l a r d i a g n o s t i c i m p o r t f o r c h i l d r e n w i t h l e a r n i n g p r o b l e m s , a s t h e i r C o d i n g s c o r e s d e v i a t e s u b s t a n t i a l l y f r o m a l l o t h e r s u b t e s t s ( T a b a c h n i c k , 1 9 7 9 ) . T h i s f i n d i n g h a s b e e n s u p p o r t e d by R u g e l ' s (1974) r e v i e w o f 25 s t u d i e s w h i c h s h o w e d t h a t d i s a b l e d r e a d e r s ' l o w e s t s c o r e s were i n t h e \" s e q u e n t i a l \" c a t e g o r y o f a WISC-R f a c t o r a n a l y s i s , a c a t e g o r y w h i c h i n c l u d e s C o d i n g . L y l e & G o y e n ( 1 9 6 9 ) h a v e c l a i m e d t h a t C o d i n g d i f f e r e n t i a t e d between n o r m a l and r e t a r d e d r e a d e r s . B u r k s a n d B r u c e (1955) have r e p o r t e d t h a t t h e C o d i n g s u b t e s t was t h e most d i f f i c u l t f o r p o o r r e a d e r s . R a s k i n e t a l . (1978) f o u n d a good c o r r e l a t i o n between t h e WISC-R A r i t h m e t i c and C o d i n g s u b t e s t s and t h e B i n e t IQ f o r d e v e l o p m e n t a l l y d i s a b l e d c h i l d r e n . V a n c e e t a l . ( 1 9 8 0 ) f o u n d t h a t l e a r n i n g d i s a b l e d c h i l d r e n had t h e l o w e s t s c o r e s on t h e A r i t h m e t i c , D i g i t Span and C o d i n g s u b t e s t s o f t h e WISC-R. No r e s e a r c h h a s b e e n r e p o r t e d , however, where C o d i n g has been i n v e s t i g a t e d a s a s i n g l e m e a s u r e o f l e a r n i n g a b i l i t y o r p o t e n t i a l . .3 T h i s r e s e a r c h seems t o s u g g e s t t h a t t h e C o d i n g t e s t has t h e a b i l i t y t o d i f f e r e n t i a t e b e t w e e n c h i l d r e n o f n o r m a l l e a r n i n g a b i l i t y and c h i l d r e n w i t h a l e a r n i n g p r o b l e m . One way t o i n v e s t i g a t e f u r t h e r i f C o d i n g m e a s u r e s t h e a b i l i t y t o l e a r n w o u l d be by u s i n g i t i n a t e s t - r e t e s t s i t u a t i o n . T e s t - R e t e s t Method w i t h C o d i n g S c o r e s . Some r e s e a r c h e r s , n o t a b l y F e u e r s t e i n (1979) and B u d o f f (1972) c l a i m t h a t l e a r n i n g p o t e n t i a l o r a b i l i t y c a n be m e a s u r e d b y t e s t i n g a c h i l d o n c e and t h e n r e a d m i n i s t e r i n g t h e same t e s t o r t e s t s . I f t h e r e i s a g a i n o n t h e s e c o n d a d m i n i s t r a t i o n t h e y c l a i m t h a t t h i s i n d i c a t e s s o m e t h i n g has b e e n l e a r n e d i n t h e i n t e r v a l b e t w e e n t h e t e s t s t o c a u s e t h e g a i n ( g r e a t e r g a i n means more has been l e a r n e d ) . T e s t - r e t e s t s t u d i e s on n o r m a l p o p u l a t i o n s u s i n g t h e WISC-R show a mean g a i n o n t h e s e c o n d a d m i n i s t r a t i o n o f t h e C o d i n g s u b t e s t , p r o b a b l y i n d i c a t i n g a s i g n i f i c a n t p r a c t i c e e f f e c t ( M a t a r r a z z o e t a l . , 1 9 73; Q u e r e s h i , 1 9 68; Tuma & Appelbaum, 1 9 8 0 ) . O t h e r t e s t - r e t e s t s t u d i e s w i t h t h i s t e s t s h o w n o n - s i g n i f i c a n t p r a c t i c e e f f e c t s among s t u d e n t s w i t h l e a r n i n g p r o b l e m s ( L o m b a r d & R e i d e l , 1 9 7 8 ) . C a t r o n & C a t r o n ( 1 9 7 7 ) f o u n d t h e same r e s u l t s f o r e d u c a b l y r e t a r d e d s t u d e n t s . One s t u d y ( S o l l y , 1977) i n w h i c h g i f t e d s t u d e n t s were compared w i t h r e t a r d e d s t u d e n t s f o u n d a s i g n i f i c a n t l y g r e a t e r g a i n f o r t h e g i f t e d on a C o d i n g s u b t e s t r e a d m i n i s t r a t i o n . T h e t i m e i n t e r v a l b e t w e e n t e s t a d m i n i s t r a t i o n s f o r t h e s e s t u d i e s was between o n e d a y a n d a y e a r . I t i s s i g n i f i c a n t t o n o t e t h a t t h e l e n g t h o f t i m e b e t w e e n a d m i n i s t r a t i o n s was n o t i m p o r t a n t a s i n a l l c a s e s t h e r e was a s i g n i f i c a n t p r a c t i c e e f f e c t f o r n o r m a l a n d n o s i g n i f i c a n t p r a c t i c e e f f e c t f o r s t u d e n t s w i t h l e a r n i n g p r o b l e m s . The r e l a t i v e s i z e o f t h e g a i n f o r n o r m a l s t u d e n t s was g r e a t e r , h o w e v e r , w i t h a s h o r t e r t i m e i n t e r v a l b e t w e e n a d m i n i s t r a t i o n s . E x c e p t p e r h a p s f o r S o l l y ' s ( 1 9 7 7 ) s t u d y w h i c h compared g i f t e d t o l e a r n i n g d i s a b l e d s t u d e n t s , no r e s e a r c h i s r e p o r t e d i n w h i c h t e s t - r e t e s t d a t a o n t h e WISC-R C o d i n g s u b t e s t f o r n o r m a l s t u d e n t s i s compared t o s t u d e n t s w i t h l e a r n i n g p r o b l e m s . S u c h a c o m p a r i s o n c o u l d be i m p o r t a n t t o i n v e s t i g a t e w h e t h e r t h e r e a r e s i g n i f i c a n t d i f f e r e n c e s i n p r a c t i c e e f f e c t s o f a n o r m a l p o p u l a t i o n a s c o m p a r e d t o a p o p u l a t i o n w i t h l e a r n i n g d i f f i c u l t i e s . Summary S i n c e r e s e a r c h seems t o s u g g e s t t h a t C o d i n g s c o r e s on t h e WISC-R s u b t e s t c a n d i f f e r e n t i a t e b e t w e e n n o r m a l s t u d e n t s and t h o s e w i t h l e a r n i n g p r o b l e m s , a n d s i n c e i t seems t h a t t h i s d i f f e r e n c e c a n be me a s u r e d by t h e t e s t - r e t e s t method, t h i s may s u g g e s t u s i n g C o d i n g s c o r e s a s a p o s s i b l e measure o f l e a r n i n g p o t e n t i a l . I t a l s o i n d i c a t e s t h e i m p o r t a n c e o f e x p l o r i n g t h e u s e o f a t e s t - r e t e s t d i f f e r e n c e i n C o d i n g s c o r e s w i t h a l e a r n i n g d i s a b l e d p o p u l a t i o n . P u r p o s e o f t h e S t u d y R e s e a r c h s u g g e s t s t h a t n o r m a l s t u d e n t s w i l l h a v e a h i g h e r mean g a i n on t h e s e c o n d a d m i n i s t r a t i o n o f t h e C o d i n g s u b t e s t t h a n l e a r n i n g d i s a b l e d s t u d e n t s . I t a l s o s u g g e s t s t h a t t h i s s u b t e s t c a n d i f f e r e n t i a t e b e t w e e n t h e two g r o u p s o f s t u d e n t s . . 5 The p r e s e n t s t u d y p r o p o s e s t o compare t h e p r a c t i c e e f f e c t s o f n o r m a l s t u d e n t s v e r s u s l e a r n i n g d i s a b l e d s t u d e n t s on t h e C o d i n g s u b t e s t . I t a s k s , w i l l t h e r e be a d i f f e r e n c e between t h e two g r o u p s and i f s o w i l l t h e d i f f e r e n c e be s i g n i f i c a n t , i n d i c a t i n g t h e n eed f o r f u r t h e r s t u d y i n t h i s a r e a . The c l a s s i f i c a t i o n o f s u b j e c t s i n t o two g r o u p s , e i t h e r l e a r n i n g d i s a b l e d o r n o r m a l was a c c o r d i n g t o w h e t h e r t h e y h a d b e e n r e f e r r e d t o a P r o v i n c i a l r e g i o n a l c e n t e r f o r l e a r n i n g d i s a b l i l i t e s as w e l l a s t h e i r s c o r e s o n a c u r r e n t a c h i e v e m e n t t e s t . An a c h i e v e m e n t t e s t was e mployed b e c a u s e t h e m a i n a r e a s o f l e a r n i n g a s m e a s u r e d by a c h i e v e m e n t t e s t s , s u c h a s r e a d i n g , a r i t h m e t i c a n d s p e l l i n g h a v e a l l b e e n c o r r e l a t e d w i t h t h e C o d i n g s u b t e s t ( D e r n e r e t al'.., 1950; H a l e , 1978; L y l e & G o y e n , 1969; R a s k i n e t a l . , 1 9 7 8 ) . The s u b j e c t s ' a c h i e v e m e n t t e s t s c o r e s w o u l d a l s o b e c o m p a r e d t o t h e i r C o d i n g s c o r e s i n o r d e r t o f u r t h e r i n v e s t i g a t e t h e d i a g n o s t i c q u a l i t i e s o f t h e C o d i n g s u b t e s t . T h e a c h i e v e m e n t t e s t s e l e c t e d f o r t h i s s t u d y was t h e B r i t i s h C o l u m b i a Q u i c k I n d i v i d u a l E d u c a t i o n a l T e s t ( B . C . Q.U.I.E.T.) ( W o r m e l i , 1 9 8 2 ) . T h i s t e s t was s e l e c t e d b e c a u s e i t was n o r m e d i n B r i t i s h C o l u m b i a a n d t h u s more v a l i d f o r t h e p o p u l a t i o n s a m p l e o f t h e s t u d y t h a n o t h e r a c h i e v e m e n t t e s t s . A s w e l l i t c o n s i s t s o f S p e l l i n g , A r i t h m e t i c , W o r d I d e n t i f i c a t i o n and P a s s a g e C o m p r e h e n s i o n , a l l a r e a s o f a c a d e m i c l e a r n i n g w h i c h have been c o r r e l a t e d i n p r e v i o u s s t u d i e s w i t h C o d i n g . T h e a u t h o r a l s o c l a i m s i t has t h e a b i l i t y t o i d e n t i f y a l e a r n i n g d i s a b l e d p o p u l a t i o n ( W o r m e l i , 1 9 8 2 ) . . 6 I n summary t h e n , t h i s s t u d y w i l l c o m p a r e t h e t e s t - r e t e s t s c o r e s o f l e a r n i n g d i s a b l e d a n d n o r m a l s t u d e n t s o n t h e W I S C - R C o d i n g s u b t e s t . I t w i l l f u r t h e r e x a m i n e r e l a t i o n s h i p s b e t w e e n s u b j e c t s C o d i n g s c o r e s a n d t h e i r c u r r e n t a c h i e v e m e n t t e s t s c o r e s a s m e a s u r e d by t h e B . C . Q . U . I . E . T . R e s e a r c h Q u e s t i o n s T h i s s t u d y was d e s i g n e d t o a n s w e r t h e f o l l o w i n g r e s e a r c h q u e s t i o n s : 1. W i l l t h e r e be a s i g n i f i c a n t mean g a i n i n t e s t - r e t e s t s c o r e s o n t h e W I S C - R C o d i n g s u b t e s t f o r \" n o r m a l \" s t u d e n t s o v e r a 1-2 d a y p e r i o d ? 2 . W i l l t h e r e be a s t a t i s t i c a l l y n o n - s i g n i f i c a n t mean g a i n i n t e s t - r e t e s t s c o r e s o n t h e W I S C - R C o d i n g s u b t e s t f o r \" l e a r n i n g d i s a b l e d \" s t u d e n t s o v e r a 1-2 day p e r i o d ? 3. W i l l t h e \" n o r m a l \" s t u d e n t s h a v e a s i g n i f i c a n t l y h i g h e r s c o r e o n t h e i n i t i a l a d m i n i s t r a t i o n a n d r e t e s t o f t h e W I S C - R C o d i n g s u b t e s t t h a n t h e \" l e a r n i n g d i s a b l e d \" s t u d e n t s ? 4. I s t h e r e a c o r r e l a t i o n b e t w e e n t h e i n i t i a l a n d r e t e s t WISC-R C o d i n g s c o r e s a n d s c o r e s f r o m t h e B . C . Q . U . I . E . T . f o r \" l e a r n i n g d i s a b l e d \" a n d \" n o r m a l \" s t u d e n t s , f i r s t s e p a r a t e l y a n d t h e n c o m b i n e d ? 5. W i l l a c o m b i n a t i o n o f t h e t e s t - r e t e s t s c o r e s o f t h e WISC-R C o d i n g s u b t e s t p l u s t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . d i f f e r e n t i a t e b e t w e e n t h e \" n o r m a l \" s t u d e n t s a n d t h e \" l e a r n i n g d i s a b l e d \" s t u d e n t s ? H y p o t h e s e s 1. T h e r e w i l l b e no s t a t i s t i c a l l y s i g n i f i c a n t t e s t - r e t e s t mean s c o r e d i f f e r e n c e on t h e C o d i n g s u b t e s t f o r \" n o r m a l \" s t u d e n t s a t t h e .05 c o n f i d e n c e l e v e l . 2. T h e r e w i l l be no s t a t i s t i c a l l y s i g n i f i c a n t t e s t - r e t e s t mean s c o r e d i f f e r e n c e o n t h e C o d i n g s u b t e s t f o r \" l e a r n i n g d i s a b l e d \" s t u d e n t s a t t h e .05 c o n f i d e n c e l e v e l . 3. T h e r e w i l l be no s t a t i s t i c a l l y s i g n i f i c a n t mean s c o r e d i f f e r e n c e b e t w e e n \" n o r m a l \" a n d \" l e a r n i n g d i s a b l e d \" s t u d e n t s on t h e i n i t i a l a nd r e t e s t C o d i n g s c o r e a t t h e .05 c o n f i d e n c e l e v e l . 4. T h e r e w i l l be no s t a t i s t i c a l l y s i g n i f i c a n t c o r r e l a t i o n b etween t h e C o d i n g s u b t e s t s c o r e s a n d e a c h o f t h e f o u r s u b t e s t s c o r e s o f t h e B.C.Q.U.I.E.T. f o r b o t h \" n o r m a l \" and \" l e a r n i n g d i s a b l e d \" s t u d e n t s , f i r s t s e p a r a t e l y and t h e n c o m b i n e d , a t t h e .05 c o n f i d e n c e l e v e l . 5. T h e r e w i l l b e no s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e b e tween t h e \" n o r m a l \" and \" l e a r n i n g d i s a b l e d \" s t u d e n t s on t h e c o m b i n e d mean s c o r e o f t h e WISC-R C o d i n g t e s t and t h e f o u r s u b t e s t s o f t h e B.C.Q.U.I.E.T. .8 D e f i n i t i o n o f Terms 1. A c a d e m i c L e a r n i n g - I s d e f i n e d a s t h e t y p e o f l e a r n i n g t h a t t a k e s p l a c e i n s c h o o l s d u r i n g s t u d e n t s ' r e g u l a r c o u r s e s o f s t u d y , s u c h a s l a n g u a g e a r t s and a r i t h m e t i c a s m e a s u r e d by t h e B.C.Q.U.I.E.T. 2. A c a d e m i c M a t e r i a l - I s d e f i n e d a s t h e t y p e o f m a t e r i a l a s t u d e n t i s a s k e d t o m a s t e r i n s c h o o l . 3. L e a r n i n g A b i l i t i e s - I s d e f i n e d a s t h e a b i l i t y o f a s t u d e n t t o m a s t e r a c a d e m i c m a t e r i a l . T h i s may be what he has l e a r n e d i n t h e p a s t a s me a s u r e d by a c h i e v e m e n t t e s t s s u c h a s t h e B.C. Q . U . I . E . T . , o r what he c a n be e x p e c t e d t o l e a r n i n t h e f u t u r e , t h e n c a l l e d l e a r n i n g p o t e n t i a l . 4 . L e a r n i n g P o t e n t i a l - I s u s e d h e r e t o m e a s u r e t h e f u t u r e c a p a c i t y o f a s t u d e n t t o l e a r n a c a d e m i c m a t e r i a l . 5. Normal S t u d e n t s - R e f e r s t o s t u d e n t s i n p u b l i c s c h o o l s who h a v e no known l e a r n i n g d i s a b i l i t i e s a n d a n a v e r a g e t o above a v e r a g e IQ as m e a s u r e d by t h e i r s c o r e s on t h e B.C.Q.U.I.E.T. 6. L e a r n i n g D i s a b l e d S t u d e n t s - A r e d e f i n e d a s t h o s e who a r e more t h a n one y e a r b e h i n d i n two o r more s c h o o l s u b j e c t s , o r who a r e i n a n i n a p p r o p r i a t e a g e / g r a d e l e v e l , b u t have a v e r a g e t o a bove IQ's a s me a s u r e d by t h e WISC-R. Summary T h e s i g n i f i c a n c e o f t h i s s t u d y w i l l be t o i n v e s t i g a t e w h e t h e r o r n o t t h e C o d i n g s u b t e s t o f t h e WISC-R i s a measure o f l e a r n i n g a b i l i t y a s i n d i c a t e d by Ross ( 1 9 7 7 ) . I t w i l l f u r t h e r a t t e m p t t o s e e i f t h i s t e s t c o r r e l a t e s t o a r e a s o f a c a d e m i c l e a r n i n g a s m e a s u r e d by an a c h i e v e m e n t t e s t , t h e t e s t s e l e c t e d . 9 f o r t h i s s t u d y b e i n g t h e B . C . Q . U . I . E . T . i n v i e w o f i t s v a l i d i t y . T h i s w i l l b e d o n e b y t e s t i n g t h e f i v e h y p o t h e s e s l i s t e d e a r l i e r . As t h i s i s a p r e l i m i n a r y s t u d y and i n v o l v e s r e l a t i v e l y s m a l l p o p u l a t i o n s t h e r e s u l t s o f t h i s s t u d y may n o t be w i d e l y g e n e r a l i z e d . However i t i s hoped t h a t t h i s s t u d y may i n d i c a t e a n e e d f o r f u r t h e r r e s e a r c h i n t h e a r e a o f m e a s u r i n g l e a r n i n g p o t e n t i a l and t h e u s e o f t h e WISC-R C o d i n g s u b t e s t as a t o o l f o r a c h i e v i n g t h i s . I n t h e n e x t c h a p t e r t h e l i t e r a t u r e d e a l i n g w i t h t h e p e r f o r m a n c e o f s u b j e c t s on t h e WISC-R and e s p e c i a l l y t h e C o d i n g s u b t e s t w i l l be r e v i e w e d a l o n g w i t h how t h i s s u b t e s t r e l a t e s t o t h e r e s t o f t h e WISC-R and o t h e r t e s t s . A l s o r e v i e w e d w i l l be t h e l i t e r a t u r e d e a l i n g w i t h t e s t - r e t e s t s t u d i e s on t h e WISC-R. I n C h a p t e r T h r e e t h e m e t h o d a n d p r o c e d u r e s o f t h i s s t u d y as w e l l a s s e l e c t i o n o f t h e s u b j e c t s and a n a l y s i s o f t h e d a t a w i l l b e d e s c r i b e d . C h a p t e r F o u r w i l l d e s c r i b e t h e r e s u l t s a n d a n a l y s i s o f t h e d a t a . C h a p t e r F i v e w i l l d i s c u s s t h e i m p l i c a t i o n s and l i m i t a t i o n s o f t h i s s t u d y and p r e s e n t a v i e w f o r f u r t h e r r e s e a r c h . . 10 CHAPTER II A R e v i e w o f t h e L i t e r a t u r e T h e r e v i e w o f t h e l i t e r a t u r e i s o r g a n i z e d a r o u n d s i x main a r e a s o f i n t e r e s t . I t r e v i e w s l i t e r a t u r e r e l e v a n t t o t h i s s t u d y i n : - p r o b l e m s o f a s s e s s m e n t i n l e a r n i n g p o t e n t i a l ; - u s e o f W e c h s l e r ' s C o d i n g S u b t e s t a n d o t h e r m e a s u r e s o f l e a r n i n g a b i l i t y , t o a s s e s s r e t a r d e d r e a d e r s , and t o t e s t E d u c a b l y M e n t a l l y R e t a r d e d s u b j e c t s ; f a c t o r s t r u c t u r e and t e s t s c a t t e r o f t h e W e c h s l e r S c a l e s ; - v a l i d i t y o f C o d i n g a n d i t s u s e as a measure o f l e a r n i n g p o t e n t i a l ; - t e s t - r e t e s t p r o c e d u r e s a s a m e a s u r e o f l e a r n i n g a b i l i t y ; and - p r a c t i c e e f f e c t s on WISC-R C o d i n g and o t h e r s u b t e s t s , and i t s u s e as a measure o f l e a r n i n g p o t e n t i a l . P r o b l e m s o f A s s e s s m e n t T h e p r o b l e m o f m e a s u r i n g a n i n d i v i d u a l ' s l e a r n i n g p o t e n t i a l h a s e x i s t e d f r o m t h e e a r l i e s t d e v e l o p m e n t o f i n t e l l e c t u a l a s s e s s m e n t . T h o r n d i k e ( 1 9 2 6 ) c o m p l a i n e d a b o u t e x i s t i n g i n t e l l i g e n c e t e s t s i n t h a t t h e y d i d n o t d i r e c t l y m e a s u r e a n i n d i v i d u a l ' s a b i l i t y t o l e a r n m o r e t h i n g s , m o r e q u i c k l y t h a n a n o t h e r i n d i v i d u a l . S a t t l e r ( 1 9 8 2 ) a n d R o s s ( 1 9 7 7 ) c l a i m e d t h a t w h a t i n t e l l i g e n c e t e s t s do m e a s u r e i s a c q u i r e d k nowledge and t h a t t h e y y i e l d an e s t i m a t e o f a c h i l d ' s c u r r e n t l e v e l o f p e r f o r m a n c e . I n f a c t , S a t t l e r (1982) c l a i m e d t h a t \" i t i s d a n g e r o u s t o make i n f e r e n c e s f r o m t h e c u r r e n t l e v e l . 11 o f p e r f o r m a n c e t o a n o t h e r l e v e l ( c a l l e d i n a t e p o t e n t i a l ) b e c a u s e we c a n n o t o b s e r v e p o t e n t i a l \" ( p . 5 0 ) . Hardy e t a l . ( 1976 ) c o n d u c t e d a s t u d y o f 200 i n n e r c i t y c h i l d r e n ( 7 7 % b l a c k , 23% w h i t e ) , who w e r e e a c h g i v e n a l l s u b t e s t s o f t h e WISC. The mean F u l l S c a l e I.Q. was 96. Then t h e I n f o r m a t i o n , C o m p r e h e n s i o n , V o c a b u l a r y , D i g i t s Backward and P i c t u r e A r r a n g e m e n t s u b t e s t s w e r e r e a d m i n i s t e r e d u s i n g a s t r u c t u r e d s e t o f p r o b i n g q u e s t i o n s t o a s c e r t a i n t h e r e a s o n f o r t h e c h i l d ' s r e s p o n s e . T h e s e r e s p o n s e s w e r e s c o r e d f o r c o r r e c t n e s s i f t h e r e s p o n s e was n o t a c c o r d i n g t o t h e manual b u t was a c c e p t a b l e t o t h e r e s e a r c h e r s i n v i e w o f t h e c h i l d ' s b a c k g r o u n d . The r e s u l t s y i e l d e d a s i g n i f i c a n t mean i n c r e a s e i n a l l t h e r e a dm i n i s t e r e d t e s t s a t t h e .001 l e v e l . T h e c o n c l u s i o n s drawn f r o m t h i s s t u d y were t h a t f o r I.Q.'s o b t a i n e d on a s t a n d a r d i z e d t e s t , t h e WISC may n o t be a v a l i d e s t i m a t e o f t h e i n t e l l e c t u a l c a p a b i l i t i e s o f i n n e r c i t y c h i l d r e n . T h i s v i e w , t h a t i n t e l l e c t u a l p o t e n t i a l c a n n o t be me a s u r e d has b e e n c h a l l e n g e d by o t h e r r e s e a r c h e r s . Kaufman c l a i m s t h a t \" I n t e l l i g e n c e q u o t i e n t s a r e u s e d t o p r e d i c t a b i l i t y t o l e a r n i n s c h o o l , a n d t h e c l o s e t h e o r e t i c a l r e l a t i o n s h i p b e t w e e n i n t e l l i g e n c e a n d l e a r n i n g a b i l i t y i s i n d i s p u t a b l e \" (Kaufman, 1 9 7 9 , p g . 5 ) . He g o e s f u r t h e r t o s t a t e t h a t t h e A n i m a l H o u s e / C o d i n g / D i g i t Symbol s u b t e s t o f t h e W e c h s l e r s c a l e s c a n be t h o u g h t o f a s a c t u a l l e a r n i n g t a s k s . T h i s i s s u p p o r t e d by Ross who s t a t e s t h a t \" C o d i n g , i n f a c t , i s b e s t v i e w e d as a t e s t o f a b i l i t y t o a c q u i r e new l e a r n i n g \" ( R o s s , 1977, pg. 7 9 ) . To f u r t h e r s u p p o r t t h e c o n c e p t t h a t t h e C o d i n g s u b t e s t o f t h e WISC-R may be a m e a s u r e o f l e a r n i n g p o t e n t i a l , t h e n e x t .12 s e c t i o n w i l l e x a m i n e s t u d i e s o n t h e W e c h s l e r I n t e l l i g e n c e s c a l e s . I t w i l l be d i v i d e d i n t o two p a r t s . T h e f i r s t w i l l d e a l w i t h t h e u s e o f t h e W e c h s l e r S c a l e s w i t h l e a r n i n g d i s a b l e d p o p u l a t i o n s . The s e c o n d p a r t w i l l e x a m i n e f a c t o r a n a l y t i c s t u d i e s o f t h e W e c h s l e r S c a l e s a n d m o r e s p e c i f i c a l l y t h e u n i q u e n e s s o f t h e C o d i n g s u b t e s t . W e c h s l e r I n t e l l i g e n c e S c a l e s and L e a r n i n g D i s a b l e d P o p u l a t i o n s T h e f i r s t s u b s e c t i o n w i l l r e v i e w t h e p e r f o r m a n c e o f d i s a b l e d r e a d e r s o n t h e WISC. T h e s e c o n d s u b s e c t i o n w i l l r e v i e w s t u d i e s a n a l y z i n g t h e p e r f o r m a n c e o f s u b j e c t s w i t h v a r i o u s l e a r n i n g p r o b l e m s . P e r f o r m a n c e o f D i s a b l e d R e a d e r s on WISC S u b t e s t s . B u r k s & B r u c e (1955) f o u n d t h a t p o o r r e a d e r s who were one o r more y e a r s b elow g r a d e l e v e l on t h e r e a d i n g p a r t o f t h e WRAT r a n k e d l o w e s t i n I n f o r m a t i o n , A r i t h m e t i c , C o d i n g a n d D i g i t S p a n . T h e y c o n c l u d e d t h a t t h e C o d i n g s u b t e s t i s t h e m o s t o u t s t a n d i n g l y d i f f i c u l t s u b t e s t f o r p o o r r e a d e r s . McLeod (1965) f o u n d a s i m i l a r r e s u l t when he r e p o r t e d a s t u d y o f 177 s u c c e s s f u l and 116 u n s u c c e s s f u l r e a d e r s . I n t h i s s t u d y a c o m p a r i s o n was made b e t w e e n t h e s u b j e c t s ' s c o r e s on e l e v e n o f t h e s u b t e s t s o f t h e WISC. When a d j u s t m e n t s were made f o r d i f f e r e n c e s i n V e r b a l IQ (VIQ) o r F u l l S c a l e IQ ( F S I Q ) , t h e r e t a r d e d r e a d i n g g r o u p s c o r e d s i g n i f i c a n t l y l o w e r t h a n t h e s u c c e s s f u l r e a d e r s o n I n f o r m a t i o n , V o c a b u l a r y , A r i t h m e t i c , D i g i t S p a n a n d C o d i n g . However, w h i l e I n f o r m a t i o n , V o c a b u l a r y and A r i t h m e t i c c o r r e l a t e d s i g n i f i c a n t l y w i t h b o t h FSIQ and VIQ f o r b o t h g r o u p s , n e i t h e r D i g i t S p a n n o r C o d i n g h a d a . 13 s i g n i f i c a n t c o r r e l a t i o n w i t h IQ f o r e i t h e r g r o u p . McLeod a l s o l i s t e d e i g h t o t h e r s t u d i e s w h i c h f o u n d C o d i n g t o be weak i n r e a d i n g d i s a b l e d s t u d e n t s . I n a c a r e f u l l y c o n t r o l l e d s t u d y o f 54 r e t a r d e d a n d 54 a d e q u a t e r e a d e r s , L y l e & Goyen (1969) f o u n d t h a t IQ d i f f e r e n c e s b e t w e e n t h e t w o g r o u p s were due p r i n c i p a l l y t o d i f f e r e n c e s i n I n f o r m a t i o n , A r i t h m e t i c a n d C o d i n g s u b t e s t s . They s p e c u l a t e d t h a t a d i s a b i l i t y i n t h e a r e a o f C o d i n g may a l s o be r e s p o n s i b l e f o r t h e p o o r p e r f o r m a n c e i n I n f o r m a t i o n a n d A r i t h m e t i c . T h i s s u g g e s t s a n u n d e r l y i n g common t h r e a d l i n k i n g t h e s e t h r e e s u b t e s t s . R u g e l ( 1 9 7 4 ) r e v i e w e d 25 s t u d i e s w h i c h r e p o r t e d WISC s u b t e s t s c o r e s f o r d i s a b l e d r e a d e r s . T h e s u b t e s t s w e r e r e c l a s s i f i e d i n t o c a t e g o r i e s l a b e l l e d : S p a t i a l , C o n c e p t u a l and S e q u e n t i a l a n d d i s a b l e d r e a d e r s w e r e r a n k e d a s t o t h e i r r e l a t i v e s t r e n g t h i n t h e s e c a t e g o r i e s . He f o u n d t h a t d i s a b l e d r e a d e r s s c o r e d l o w e s t i n t h e s e q u e n t i a l c a t e g o r y w h i c h i n c l u d e d t h e C o d i n g and D i g i t Span S u b t e s t s . P e r f o r m a n c e o f S u b j e c t s w i t h L e a r n i n g P r o b l e m s o n t h e WISC-R. H a l e (19 78) a d m i n i s t e r e d b o t h t h e WRAT and WISC-R t o 155 r e f e r r e d c h i l d r e n i n N e b r a s k a . A 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 c o n d u c t e d w h e r e V I Q a n d P I Q s c o r e s w e r e j o i n t l y r e g r e s s e d o n R e a d i n g , S p e l l i n g and A r i t h m e t i c s t a n d a r d s c o r e s f r o m t h e WRAT. T h e r e s u l t s i n d i c a t e d t h a t P I Q d i d n o t s i g n i f i c a n t l y p r e d i c t a c a d e m i c a c h i e v e m e n t a n d t h a t V I Q s i g n i f i c a n t l y p r e d i c t e d R e a d i n g a n d A r i t h m e t i c s c o r e s . No i n d i v i d u a l s u b t e s t s c o r e s were r e p o r t e d i n t h i s s t u d y a l t h o u g h i t w o u l d have been i n t e r e s t i n g t o s e e t h e r e s u l t s o f t h i s w i t h .14 C o d i n g , e s p e c i a l l y s i n c e o t h e r r e s e a r c h e r s h a v e s u g g e s t e d t h a t C o d i n g m i g h t p o s s i b l y be p a r t o f t h e V I Q s c a l e o f t h e WISC ( L y l e & Goyen, 1969; McLeod, 1 9 6 5 ) . R a s k i n e t a l . ( 1 9 7 8 ) r e p o r t e d a s t u d y i n w h i c h 50 c h i l d r e n , a g e d 6-1 t o 1 0 - 1 1 , who w e r e r e f e r r e d f o r p o s s i b l e m e n t a l r e t a r d a t i o n o r l e a r n i n g d i s a b i l i t i e s , were a d m i n i s t e r e d a b a t t e r y o f t e s t s . The b a t t e r y i n c l u d e d t h e WISC-R, S t a n f o r d B i n e t , B e n d e r VMG, B e e r y D e v e l o p m e n t a l t e s t o f VMI, a n d t h e R e a d i n g , S p e l l i n g , M a t h s u b t e s t s o f t h e WRAT. A s i g n i f i c a n t c o r r e l a t i o n was f o u n d between t h e WISC-R A r i t h m e t i c , D i g i t Span and C o d i n g s u b t e s t s and t h e B i n e t I Q. I n v i e w o f t h e f a c t t h a t t h e B i n e t i s l a n g u a g e o r i e n t e d a n d c o r r e l a t e s s i g n i f i c a n t l y w i t h t h e V e r b a l IQ o f t h e WISC-R ( r = . 8 4 ) , t h i s f i n d i n g l e n d s c r e d e n c e t o t h e i d e a t h a t t h e A r i t h m e t i c , D i g i t Span and C o d i n g s u b t e s t o f t h e WISC-R may be i m p o r t a n t i n t h e a s s e s s m e n t o f l a n g u a g e r e l a t e d l e a r n i n g d i s a b i l i t i e s . V a n c e , S i n g e r and E n g i n (1980) c o n d u c t e d a s t u d y t o answer t w o q u e s t i o n s : f i r s t , t o d e t e r m i n e w h e t h e r a n y s u b t e s t d i f f e r e n c e s e x i s t e d b e t w e e n l e a r n i n g d i s a b l e d m a l e s a n d f e m a l e s ; a n d s e c o n d l y , i f t h e d i s c r e p a n c y b e t w e e n t h e WISC-R VIQ and PIQ was s i g n i f i c a n t f o r t h i s s a m p l e , and i f i t was o f d i a g n o s t i c i m p o r t a n c e . T h e WISC-R was a d m i n i s t e r e d t o t h e s u b j e c t s f o r t h i s s t u d y who w e r e 98 c h i l d r e n ( 6 - 3 t o 13-6 y e a r s ; 69 m a l e s , 29 f e m a l e s ) who h a d b e e n l a b e l l e d l e a r n i n g d i s a b l e d . R e s u l t s o f t h i s s t u d y i n d i c a t e d t h a t b o t h m a l e s a n d f e m a l e s o b t a i n e d s i g n i f i c a n t l y h i g h e r s c o r e s o n P i c t u r e A r r a n g e m e n t , O b j e c t A s s e m b l y , V o c a b u l a r y a n d S i m i l a r i t i e s . F u r t h e r , f e m a l e s s c o r e d s i g n i f i c a n t l y h i g h e r t h a n m a l e s o n .15 C o d i n g . F i n a l l y t h i s s t u d y a g a i n p o i n t e d o u t t h a t t h e l o w e s t s c o r e s f o r a l l s u b j e c t s w e r e o n t h e A r i t h m e t i c , D i g i t Span and C o d i n g S u b t e s t s . I n summary, when t h e l i t e r a t u r e on t h e W e c h s l e r s c a l e s and t h e i r r e l a t i o n s h i p t o l e a r n i n g p r o b l e m s i s a n a l y z e d i t seems a p p a r e n t t h a t l e a r n i n g d i s a b l e d s u b j e c t s h a v e t h e m o s t d i f f i c u l t y w i t h t h e A r i t h m e t i c , D i g i t Span and C o d i n g s u b t e s t s . T h e n e x t p a r t o f t h i s s e c t i o n w i l l r e v i e w s t u d i e s d e a l i n g w i t h t h e F a c t o r s t r u c t u r e o f t h e W e c h s l e r s c a l e s , t e s t s c a t t e r among t h e v a r i o u s s u b t e s t s a n d c o m p a r i s o n s o f t h e s u b t e s t s i n f o r m u l a t i n g h y p o t h e s i s . F a c t o r S t r u c t u r e and T e s t S c a t t e r o f W e c h s l e r S c a l e s S i n c e i t s i n c e p t i o n t h e WISC h a s b e e n s u b j e c t t o many f a c t o r a n a l y t i c s t u d i e s . E a r l i e r s t u d i e s b y C o h e n ( 1 9 5 9 ) , M a x w e l l ( 1 9 5 9 ) , B a u m e i s t e r & B a r t l e t t ( 1 9 6 2 ) , B a n n a t y n e ( 1 9 6 8 ) , and B o r t n e r & B i r c h ( 1 9 6 9 ) , l a i d t h e b a s i s f o r d i v i d i n g t h e WISC s u b t e s t s i n t o t h r e e m a i n c a t e g o r i e s . The f i r s t c a t e g o r y , o f t e n l a b e l l e d a s a v e r b a l c a t e g o r y , g e n e r a l l y i n c l u d e d t h e I n f o r m a t i o n , V o c a b u l a r y , S i m i l a r i t i e s , B l o c k D e s i g n , a n d C o m p r e h e n s i o n s u b t e s t s . The s e c o n d c a t e g o r y , o f t e n l a b e l l e d a C o n c e p t u a l o r P e r c e p t u a l c a t e g o r y , g e n e r a l l y i n c l u d e d t h e O b j e c t A s s e m b l y , P i c t u r e C o m p l e t i o n , P i c t u r e A r r a n g e m e n t and sometimes t h e A r i t h m e t i c s u b t e s t s . The t h i r d c a t e g o r y , o f t e n l a b e l l e d a d i s t r a c t i b i l i t y o r memory f a c t o r , u s u a l l y i n c l u d e d t h e D i g i t S p a n , M a z e s , C o d i n g a n d s o m e t i m e s t h e A r i t h m e t i c s u b t e s t s . A f a c t o r a n a l y s i s o f W e c h s l e r ' s s t a n d a r d i z a t i o n g r o u p f o r t h e WISC-R by Kaufman (1975) r e v e a l e d much t h e same f i n d i n g s as p r e v i o u s f a c t o r a n a l y s i s on t h e WISC. A n o t h e r s t u d y by Lombard & R i e d e l ( 1 9 7 8 ) r e p o r t e d o n a s a m p l e o f 76 s u b j e c t s who had b e e n r e f e r r e d f o r v a r i o u s l e a r n i n g p r o b l e m s . A g a i n , a f a c t o r a n a l y s i s o f t h e i r WISC-R s c o r e s i n d i c a t e d t h r e e c a t e g o r i e s w h i c h w e r e c o n s i s t e n t w i t h t h e p r e v i o u s r e s e a r c h . I n t h i s s t u d y t h e C o d i n g s u b t e s t l o a d e d v e r y h i g h l y b y i t s e l f o n a s i n g l e f a c t o r , l e a d i n g t h 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 t h e C o d i n g s u b t e s t may b e m e a s u r i n g s o m e t h i n g v e r y d i f f e r e n t f r o m t h e o t h e r p e r f o r m a n c e s u b t e s t s . B e c a u s e o f t h e u n u s u a l l o a d i n g o f t h e C o d i n g s u b t e s t on F a c t o r a n a l y t i c s t u d i e s , some r e s e a r c h e r s c l a i m t h a t t h i s s u b t e s t a l o n g w i t h A r i t h m e t i c , h as some d i a g n o s t i c a b i l i t i e s i n t e r m s o f p r o f i l e o r s c a t t e r a n a l y s i s ( K a u f m a n , 1 9 7 9 ) . T a b a c h n i c k ( 1 9 7 9 ) r e p o r t e d a s t u d y d e s i g n e d t o i n v e s t i g a t e s c a t t e r o n t h e WISC-R p r o d u c e d by a s a m p l e o f 105 l e a r n i n g d i s a b l e d c h i l d r e n o f a v e r a g e i n t e l l e c t u a l p o t e n t i a l ( I Q = 7 5 - 1 4 1 ) a n d c o m p a r i n g i t t o s c a t t e r f r o m K a u f m a n ' s ( 1 9 7 5 ) s t a n d a r d i z a t i o n sample as c o n t r o l s . No s i g n i f i c a n t d i f f e r e n c e s b e t w e e n l e a r n i n g d i s a b l e d a n d c o n t r o l s i n s c a t t e r f o r t h e V e r b a l s u b t e s t s was f o u n d . T h e r e was h o w e v e r , s i g n i f i c a n t P e r f o r m a n c e s c a l e s c a t t e r f o r t h e l e a r n i n g d i s a b l e d g r o u p as compared t o t h e c o n t r o l s . The a u t h o r c o n c l u d e s t h a t : The d i f f e r e n c e i n WISC-R s c a t t e r between learning d i s a b l e d and normal c h i l d r e n i s r e l i a b l e and produced by l e a r n i n g d i s a b l e d c h i l d r e n showing c o n s i s t e n t l y more s c a t t e r within t h e p e r f o r m a n c e s u b t e s t s and between v e r b a l and performance subtests r a t h e r t h an w i t h i n verbal subtests. Furthermore, these learning d i s a b l e d c h i l d r e n tend t o have p a r t i c u l a r d i f f i c u l t y with Coding, w i t h s c o r e s d e v i a t i n g s u b s t a n t i a l l y from a l l other subtests. This suggests that Coding s c o r e s may be o f s i n g u l a r d i a g n o s t i c import (p. 628) . . 17 I n summary t h e n , some f a c t o r a n a l y t i c r e s e a r c h o n t h e W e c h s l e r s c a l e s has r e v e a l e d t h a t t h e C o d i n g s u b t e s t m e a s u r e s s o m e t h i n g d i f f e r e n t f r o m t h e o t h e r s u b t e s t s , a n d ' e v e n f r o m t h e g e n e r a l IQ s c o r e s t h e m s e l v e s . F u r t h e r m o r e , C o d i n g seems t o have a u n i q u e a b i l i t y t o i d e n t i f y l e a r n i n g d i s a b l e d c h i l d r e n . T h e n e x t s e c t i o n w i l l r e v i e w l i t e r a t u r e d e a l i n g w i t h what t h e C o d i n g s u b t e s t m e a s u r e s a n d i f i t c a n be u s e d as a measure o f l e a r n i n g p o t e n t i a l . C o d i n g . In t h e v a r i o u s f a c t o r a n a l y t i c s t u d i e s r e v i e w e d p r e v i o u s l y , C o d i n g o f t e n l o a d e d by i t s e l f o n a f a c t o r t h e n u s u a l l y l a b e l l e d t h e d i s t r a c t i b i l i t y o r s o m e t i m e s , memory, f a c t o r . S i n c e t h i s i s a l a b e l t h a t h a s b e e n i n v e n t e d b y t h e r e s e a r c h e r s i t d o e s n o t n e c e s s a r i l y h o l d t h a t C o d i n g m e a s u r e s m a i n l y t h e d i s t r a c t i b i l i t y , a t t e n t i o n a l s k i l l s , o r m o t i v a t i o n t h a t a s u b j e c t may h a v e . In f a c t , r e s e a r c h t e n d s t o d i s p e l t h e i d e a t h a t C o d i n g i s a measure o f d i s t r a c t i b i l i t y o r m o t i v a t i o n . N a l v e n & P u l e o (1968) r e p o r t e d a s t u d y on 60 s u b j e c t s , 30 m a l e s a n d 30 f e m a l e s , r a n d o m l y s e l e c t e d f r o m g r a d e s two t o f o u r , who were e a c h a d m i n i s t e r e d t h e D i g i t Span s u b t e s t o f t h e WISC. E a c h c h i l d was t h e n r a t e d on a d i s t r a c t i b i l i t y s c a l e by h i s c l a s s r o o m t e a c h e r . The d i s t r a c t i b i l i t y m e asure had a h i g h t e s t - r e t e s t r e l i a b i l i t y o f . 9 2 . When t h e d i s t r a c t i b i l i t y r a t i n g s were i n t e r c o r r e l a t e d w i t h t h e D i g i t Span s c o r e s , i t was f o u n d t h e y were u n r e l a t e d , r ' s r a n g i n g f r o m .05 f o r raw s c o r e s t o -.07 f o r s c a l e d s c o r e s . T h e a u t h o r s c o n c l u d e d t h a t i t i s u n t e n a b l e t o c o n s i d e r D i g i t S p a n a m e a s u r e o f c l a s s r o o m d i s t r a c t i b i l i t y . S i n c e C o d i n g l o a d s w i t h D i g i t S p a n o n t h e same d i s t r a c t i b i l i t y c a t e g o r y t h i s r e s e a r c h s u p p o r t s t h e i d e a . 18 t h a t C o d i n g may n o t b e a m e a s u r e o f \u00E2\u0080\u00A2 d i s t r a c t i b i l i t y . F u r t h e r s u p p o r t f o r t h i s i d e a comes f r o m r e s e a r c h c o n d u c t e d b y L y l e & J o h n s o n (1973) who s t u d i e d t h e r e l a t i o n s h i p between p e r f o r m a n c e on t h e WISC C o d i n g s u b t e s t a n d s p e e d o f w r i t i n g and c o p y i n g s y m b o l s . T h e e f f e c t o f r e i n f o r c e m e n t o n a l l t h r e e was a l s o e x a m i n e d . The r e s e a r c h e r s compared 40 good c o d e r s ( i e . s c a l e d s c o r e s >10) t o 40 p o o r c o d e r s ( s c a l e d s c o r e s <8). An ANOVA f o u n d g o o d c o d e r s s i g n i f i c a n t l y s u p e r i o r t o p o o r c o d e r s i n s p e e d o f w r i t i n g X's and c o p y i n g s y m b o l s . R e i n f o r c e m e n t was n o t e f f e c t i v e i n i n c r e a s i n g p e r f o r m a n c e . When good and p o o r c o d e r s w e r e r a n d o m l y a s s i g n e d t o r e i n f o r c e m e n t a n d n o n - r e i n f o r c e m e n t t r e a t m e n t g r o u p s a s i g n i f i c a n t g r o u p s e f f e c t (p < .05) was f o u n d , b u t t h e t r e a t m e n t e f f e c t a n d a g r o u p x t r e a t m e n t e f f e c t was f o u n d t o be n o n - s i g n i f i c a n t . The a u t h o r s c o n c l u d e d t h a t t h e \" l a c k o f s i g n i f i c a n c e f o r any o f t h e g r o u p x t r e a t m e n t i n t e r a c t i o n s d i s c o u n t e d t h e p o s s i b i l i t y t h a t t h e d i f f e r e n c e s between good and bad c o d e r s was m e r e l y a m a t t e r o f m o t i v a t i o n \" ( p . 2 1 4 ) . T h e v i e w t h a t t h e t h i r d c a t e g o r y o f w h i c h C o d i n g i s p a r t , may n o t be a p p r o p r i a t e l y l a b e l l e d i s a l s o s u p p o r t e d b y S a t t l e r ( 1 9 8 2 ) who b e l i e v e s t h e r e i s some d i f f i c u l t y i n i n t e r p r e t i n g t h e m e a n i n g o f t h e t h i r d f a c t o r . Kaufman (1979) adds h i s s u p p o r t by s t a t i n g : I t i s easy t o see how c h i l d r e n may score very poorly on the three WISC-R s u b t e s t s c o n s t i t u t i n g the t h i r d f a c t o r because of d i s t r a c t i b l e behavior, but i t i s more d i f f i c u l t t o v i s u a l i z e c h i l d r e n s c o r i n g v e r y w e l l on t h e t h r e e subtests merely or p r i m a r i l y because of cl o s e a t t e n t i o n t o the tasks. Thus the p o s s i b i l i t y that the t h i r d f a c t o r may r e f l e c t a c o g n i t i v e a b i l i t y r a t h e r t h an a b e h a v i o r a l a t t r i b u t e i s very r e a l and must be considered as an a c t i v e hypotheses when i n t e r p r e t i n g any c h i l d ' s WISC-R p r o f i l e (p. 70). \u00E2\u0080\u00A2 1 9 F u r t h e r m o r e , no c o n c l u s i v e r e s e a r c h h a s b e e n p u b l i s h e d w h i c h s h o w s a l i n k b e t w e e n d i s t r a c t i b i l i t y o r m o t i v a t i o n and C o d i n g s c o r e s . V e r y l i t t l e r e s e a r c h h a s b e e n r e p o r t e d i n w h i c h C o d i n g a l o n e has b e e n i n v e s t i g a t e d f o r t h e p r o p e r t i e s t h a t i t - d o e s m e a s u r e . One s t u d y w h i c h d i d i n v e s t i g a t e t h e p r o p e r t i e s o f t h e C o d i n g t e s t was t h a t o f R o y e r ( 1 9 7 1 ) . A f t e r t e s t i n g 553 c o l l e g e s t u d e n t s w i t h t h e D i g i t S y m b o l s u b t e s t o f t h e WAIS, a t e s t s i m i l a r t o t h e C o d i n g s u b t e s t o f t h e WISC-R b u t normed f o r an a d u l t p o p u l a t i o n , R o y e r c o n c l u d e d t h a t t h i s s u b t e s t i s a d i r e c t m e a s u r e o f t h e r a t e o f i n f o r m a t i o n p r o c e s s i n g o f v i s u a l s y m b o l s . Among o t h e r r e s e a r c h e r s K a u f m a n (1979) c l a i m s t h a t C o d i n g r e q u i r e s a n a l y t i c a n d s e q u e n t i a l s k i l l s a n d demands a g r e a t d e a l o f l e f t - b r a i n , r i g h t - b r a i n i n t e g r a t i o n . R o s s ( 1 9 7 7 ) c l a i m s t h a t C o d i n g i s b e s t v i e w e d a s a t e s t o f t h e a b i l i t y t o a c q u i r e new l e a r n i n g . S a t t l e r (1982) c l a i m s t h a t C o d i n g : - r e q u i r e s t h e a b i l i t y t o l e a r n an u n f a m i l i a r t a s k - i n v o l v e s s p e e d and a c c u r a c y o f e y e - h a n d c o o r d i n a t i o n - i n v o l v e s a t t e n t i o n a l s k i l l s - r e q u i r e s s h o r t t e r m memory - p o s s i b l y i n v o l v e s m o t i v a t i o n - r e q u i r e s t h e a b i l i t y t o l e a r n c o m b i n a t i o n s o f s y m b o l s a n d s h a p e s - r e q u i r e s t h e a b i l i t y t o make a s s o c i a t i o n s q u i c k l y a n d a c c u r a t e l y . E s t e s ( 1 9 7 4 ) c l a i m s t h a t C o d i n g i n v o l v e s a v e r b a l e n c o d i n g p r o c e s s a s a m a j o r component. . 20 I n summary, a l t h o u g h t h e WISC-R C o d i n g s u b t e s t h a s o f t e n b e e n c l a s s i f i e d a s a m e a s u r e o f d i s t r a c t i b i l i t y , r e s e a r c h has n o t b o r n e t h i s o u t . I n s t e a d some r e s e a r c h e r s have c l a i m e d t h a t C o d i n g may r e a l l y b e m e a s u r i n g some c o g n i t i v e a b i l i t i e s . No c o n c l u s i v e s t u d i e s have been r e p o r t e d t h a t have i d e n t i f i e d what p r o p e r t i e s C o d i n g d o e s m e a s u r e . The f o l l o w i n g s e c t i o n w i l l r e v i e w what p r o p e r t i e s C o d i n g may have as a measure o f l e a r n i n g a b i l i t y a c c o r d i n g t o some r e s e a r c h e r s . V a l i d i t y o f U s i n g C o d i n g as a Measure o f L e a r n i n g A b i l i t y I n t h e p r e v i o u s l y r e v i e w e d l i t e r a t u r e t h e p r o p e r t i e s o f l e a r n i n g t h a t C o d i n g seems t o m e a s u r e h a v e been o u t l i n e d . To se e i f C o d i n g c a n be u s e f u l i n m e a s u r i n g a s u b j e c t ' s l e a r n i n g a b i l i t i e s t h i s s e c t i o n w i l l examine t h e p r o p e r t i e s w h i c h some a u t h o r s c o n s i d e r t o c o m p r i s e l e a r n i n g a b i l i t y . F i r s t , Gagne (1970) has l i s t e d s e v e n p h a s e s o f l e a r n i n g . T h e s e a r e shown i n F i g u r e 1. A n e x a m i n a t i o n o f t h e p r o p e r t i e s t h a t C o d i n g p u r p o r t s t o m e a s u r e a n d Gagne's P h a s e s o f L e a r n i n g shows t h a t i n d e e d t h e C o d i n g s u b t e s t w o u l d seem t o m e a s u r e a l l p h a s e s o f l e a r n i n g . M e r c e r ( 1 9 8 3 ) h a s l i s t e d some s e l e c t e d common l e a r n i n g d i f f i c u l t i e s o f l e a r n i n g d i s a b l e d s t u d e n t s . T h e s e a r e p r e s e n t e d i n F i g u r e 2. A g a i n a c o m p a r i s o n w i t h t h e p r o p e r t i e s t h a t C o d i n g p u r p o r t s t o m e a s u r e seems t o i n d i c a t e t h a t C o d i n g may m e a s u r e some s e l e c t e d common l e a r n i n g d i f f i c u l t i e s ' o f l e a r n i n g d i s a b l e d s t u d e n t s . F i g u r e 1 P h a s e s o f L e a r n i n g Gagne, R.M. M o t i v a t i o n A p p r e h e n s i o n A c q u i s i t i o n R e t e n t i o n & R e c a l l G e n e r a l i z a t i o n P e r f o r m a n c e F e e d b a c k l e a r n i n g e x p e r i e n c e p r o v i d e s i n c e n t i v e f o r l e a r n i n g s e l e c t i v e a t t e n t i o n m a t e r i a l t o be l e a r n e d i s s t o r e d i n memory r e t e n t i o n a n d r e c a l l i n g o f m a t e r i a l i n memory u s i n g a c q u i r e d i n f o r m a t i o n i n d i f f e r e n t c i r c u m s t a n c e s o b s e r v a b l e p r o c e s s t h a t s o m e t h i n g was l e a r n e d i n f o r m a t i o n g i v e n a s t o a d e q u a c y o f r e s p o n s e r e s u l t s i n m o t i v a t i o n -c o m p l e t i n g c y c l e F i g u r e 2 Some S e l e c t e d Common L e a r n i n g D i f f i c u l t i e s o f L e a r n i n g D i s a b l e d S t u d e n t s A f f e c t i n g Math P e r f o r m a n c e L e a r n i n g D i f f i c u l t y B e h a v i o r a l P r o b l e m P e r c e p t u a l C o p y i n g Shapes Memory R e t a i n i n g t h e meaning o f s y m b o l s B e h a v i o r P a t t e r n s A t t e n d i n g t o d e t a i l S w i t c h i n g f r o m one o p e r a t i o n t o a n o t h e r M o t o r W r i t i n g numbers l e g i b l y w i t h s p e e d and a c c u r a c y . 22 T h e l a s t s e c t i o n o f t h i s r e v i e w w i l l examine f i r s t o f a l l t h e s t u d i e s t h a t i n d i c a t e t h e f e a s i b i l i t y o f u s i n g a t e s t - r e t e s t method t o measure l e a r n i n g p o t e n t i a l . S e c o n d l y , i t w i l l r e v i e w t e s t - r e t e s t s t u d i e s t h a t haver-been c o n d u c t e d u s i n g t h e W e c h s l e r s c a l e s and more s p e c i f i c a l l y t h e C o d i n g S u b t e s t . T e s t - R e t e s t As a M e a s u r e o f L e a r n i n g A b i l i t y A number o f p r o c e d u r e s t h a t go b e y o n d s t a n d a r d a s s e s s m e n t t e c h n i q u e s have been d e v e l o p e d r e c e n t l y . T h e s e t e c h n i q u e s a r e r e v i e w e d h e r e b e c a u s e t h e y d e m o n s t r a t e one way i n w h i c h C o d i n g m i g h t p o s s i b l y be u s e d t o measure l e a r n i n g p o t e n t i a l . A l t h o u g h t h e s e p r o c e d u r e s a r e s t i l l e x p e r i m e n t a l , enough r e s e a r c h has b e e n c o n d u c t e d on them t o g i v e them a measure o f c r e d i b i l i t y . S a t t l e r has recommended s u c h t e c h n i q u e s as s u p p l e m e n t a r y p r o c e d u r e s \" t h a t c a n p r o v i d e a d d i t i o n a l i n f o r m a t i o n u s e f u l i n e v a l u a t i n g h a n d i c a p p e d c h i l d r e n and c h i l d r e n r e f e r r e d b e c a u s e o f p o o r s c h o o l p e r f o r m a n c e , a n d i n d e v e l o p i n g r e m e d i a t i o n s t r a t e g i e s \" ( S a t t l e r , 1982 , p g . 3 4 3 ) . One s u c h t e c h n i q u e i s t h e L e a r n i n g P o t e n t i a l A s s e s s m e n t p r o c e d u r e d e v e l o p e d a n d i n v e s t i g a t e d v a r i o u s l y by B u d o f f a n d h i s a s s o c i a t e s (1976) and F e u e r s t e i n ( 1 9 7 9 ) . B u d o f f a n d G o t t l i e b ( 1 9 7 6 ) r e p o r t e d t h a t t h e L e a r n i n g P o t e n t i a l A s s e s s m e n t p r o c e d u r e , w h i c h B u d o f f and h i s a s s o c i a t e s h a v e d e v e l o p e d , i s an a l t e r n a t i v e t o t r a d i t i o n a l v e r b a l l y b a s e d i n t e l l i g e n t t e s t s f o r e s t i m a t i n g g e n e r a l a b i l i t y t o r e a s o n . T h i s a s s e s s m e n t a p p r o a c h i s b a s e d o n a c o n c e p t u a l i z a t i o n o f i n t e l l i g e n c e t h a t s t r e s s e s t h e a b i l i t y o f a n i n d i v i d u a l t o p r o f i t f r o m l e a r n i n g e x p e r i e n c e s . In t h i s a s s e s s m e n t p r o c e d u r e . 23 t h e i n d i v i d u a l i s g i v e n r e a s o n i n g t a s k s w h i c h a r e a d m i n i s t e r e d i n a t e s t - t r a i n - r e t e s t s e q u e n c e . T r a i n i n g i s g i v e n b e c a u s e i t a l l o w s t h e i n d i v i d u a l t o u n d e r s t a n d how t o s o l v e p r o b l e m s whose c o n t e n t may be s t r a n g e a n d i n v o l v e s o l v i n g s t r a t e g i e s n o t r e a d i l y a p p a r e n t t o him. The t e s t s u s e d a r e an a l t e r e d v e r s i o n o f K o h s B l o c k D e s i g n s , R a v e n ' s P r o g r e s s i v e M a t r i c e s and t h e S e r i e s L e a r n i n g P o t e n t i a l Test- ( S L P T ) . The S L P T ' s m a j o r t a s k i s t h e c o m p l e t i o n o f a s e r i e s o f p i c t u r e s o r g e o m e t r i c f o r m s a r r a n g e d i n a p a t t e r n i n w h i c h t h e f i g u r e s c h a n g e s y s t e m a t i c a l l y . E a c h i t e m c o n s i s t s o f a h o r i z o n t a l row o f c e l l s e a c h o f w h i c h c o n t a i n s a s t i m u l u s f i g u r e . One c e l l i s l e f t b l a n k and t h e s u b j e c t m u s t i d e n t i f y f r o m among m u l t i p l e c h o i c e s w h i c h p i c t u r e b e s t c o m p l e t e s t h e s e r i e s . I n F o l m a n a n d B u d o f f ' s ( 1 9 7 1 ) s t u d y a n i n t e r v i e w s u r v e y was r e p o r t e d e x a m i n i n g p r e s e n t v o c a t i o n a l s t a t u s a n d d e v e l o p m e n t o f v o c a t i o n a l g o a l s i n l o w i n c o m e s p e c i a l a n d r e g u l a r c l a s s a d o l e s c e n t s . I t was f o u n d t h a t t h o s e a d o l e s c e n t s c l a s s i f i e d a s m e n t a l l y r e t a r d e d who seemed t o h a v e low l e a r n i n g p o t e n t i a l f u n c t i o n e d a s t h e m e n t a l l y r e t a r d e d a r e o f t e n d e s c r i b e d , w h i l e t h o s e who s e e m e d t o h a v e a h i g h e r l e a r n i n g p o t e n t i a l a r e e d u c a t i o n a l l y r e t a r d e d . I n a s t u d y b y B a b a d a n d B u d o f f ( 1 9 7 4 ) t h e a u t h o r s a t t e m p t e d t o i n v e s t i g a t e t h e s e n s i t i v i t y a n d v a l i d i t y o f t h e L e a r n i n g P o t e n t i a l A s s e s s m e n t p r o c e d u r e . T h e y d i v i d e d 207 w h i t e t h i r d g r a d e c h i l d r e n i n t o t h r e e g r o u p s a c c o r d i n g t o IQ s c o r e s : B r i g h t - N o r m a l , D u l l - A v e r a g e , and S u b n o r m a l . F i r s t t h e s t u d e n t s w e r e g i v e n t h e S L P T a n d some s t a n d a r d i z e d t r a i n i n g . 24 w h i l e t h e t e a c h e r s c o m p l e t e d r a t i n g s c a l e s on a l l t h e s u b j e c t s . The SLPT was g i v e n a s a p o s t t e s t t h r e e d a y s l a t e r a n d t h i s was f o l l o w e d by a t e s t o f G e n e r a l A b i l i t y s e v e r a l d a y s l a t e r by t h e same t e s t e r . The r e s u l t s i n d i c a t e d t h a t t h e l e a r n i n g p o t e n t i a l p r e d i c t i o n s f o r t h e s u b n o r m a l a n d d u l l - a v e r a g e s a m p l e w e r e h i g h e r t h a n t h e i r IQ p r e d i c t i o n s . F u r t h e r , t h e d u l l - a v e r a g e g r o u p g a i n e d f r o m p r a c t i c e s i g n i f i c a n t l y m o r e t h a n t h e s u b n o r m a l g r o u p ( t = 2.54, d f = 60, p < . 0 1 ) . I t was a l s o f o u n d t h a t b o t h t h e s u b n o r m a l a n d d u l l - a v e r a g e g r o u p g a i n e d more f r o m t r a i n i n g t h a n t h e b r i g h t n o r m a l g r o u p . T h e s e r e s u l t s i n d i c a t e d t h a t l e a r n i n g p o t e n t i a l t e s t i n g showed a h i g h e r l e v e l o f d i f f e r e n t i a t i o n among, low IQ, l o w SES s u b j e c t s t h a n a s t a n d a r d t e s t o f i n t e l l i g e n c e . U s i n g a l e a r n i n g p o t e n t i a l a s s e s s m e n t p r o c e d u r e c o n f i r m e d a c o n s i d e r a b l e a b i l i t y t o r e a s o n among low IQ c h i l d r e n w h i c h was n o t i n d i c a t e d b y c o n v e n t i o n a l s t a n d a r d m e a s u r e s o f i n t e l l i g e n c e . A s t u d y by B u d o f f a n d C o r m a n (19 74) e x a m i n e d d e m o g r a p h i c and p s y c h o m e t r i c f a c t o r s r e l a t e d t o p e r f o r m a n c e o n t h e K ohs l e a r n i n g p o t e n t i a l p r o c e d u r e . I n t h i s s t u d y d e m o g r a p h i c and f a m i l y c h a r a c t e r i s t i c s a l o n g w i t h WISC V e r b a l IQ a n d a n d S t a n f o r d - B i n e t s c o r e s f o r 627 EMR s u b j e c t s w e r e r e l a t e d t o p r e - a n d - p o s t t r a i n i n g Kohs l e a r n i n g p o t e n t i a l s c o r e s . P a r t i a l c o r r e l a t i o n c o e f f i c i e n t s b e t w e e n p e r f o r m a n c e on t h e Kohs t e s t and d e m o g r a p h i c and p s y c h o m e t r i c f a c t o r s w e r e o b t a i n e d f r o m a s t e p w i s e m u l t i p l e r e g r e s s i o n p r o c e d u r e . I t was f o u n d t h a t p o s t - t r a i n i n g K o h s s c o r e s w e r e n o t r e l a t e d t o r a c e o r S E S , w h i l e p r e - t r a i n i n g K o h s , WISC V e r b a l IQ a n d S t a n f o r d - B i n e t . 2 5 s c o r e s w e r e r e l a t e d t o f a c t o r s i n d i c a t i n g p s y c h o s o c i a l v u l n e r a b i l i t y w h e n t h e e f f e c t s o f a l l o t h e r i n d e p e n d e n t v a r i a b l e s were p a r t i a l l e d o u t . T h i s r e s u l t s u p p o r t s t h e i d e a t h a t a l e a r n i n g p o t e n t i a l a s s e s s m e n t p r o c e d u r e i s i n a s e n s e , c u l t u r e f r e e , w h i l e s t a n d a r d i z e d t e s t s o f I Q a r e o f t e n c r i t i c i z e d a s b e i n g c u l t u r a l l y b i a s e d . One s i g n i f i c a n t a s p e c t o f t h e above s t u d y was t h e u s e o f a m u l t i p l e - r e g r e s s i o n t e c h n i q u e . The use o f s i m p l e g a i n s c o r e s i n s t a t i s t i c a l a n a l y s i s h a s b e e n c r i t i c i z e d ( C r o n b a c h , 1960) b e c a u s e o f t h e u n r e l i a b i l i t y i n h e r e n t i n a s c o r e d e r i v e d f r o m t h e s u b t r a c t i o n o f p r e t e s t f r o m p o s t t e s t s c o r e s . I n t h e m u l t i p l e r e g r e s s i o n t e c h n i q u e t h e g a i n f o r e a c h s u b j e c t c a n be t h o u g h t o f as t h e d i f f e r e n c e between h i s a c t u a l s c o r e a n d h i s p r e d i c t e d s c o r e a s c a l c u l a t e d f r o m t h e r e g r e s s i o n w e i g h t s o f a g i v e n e q u a t i o n . In a y e a r l o n g s t u d y o f EMR c h i l d r e n who w e r e t e s t e d by t h e l e a r n i n g p o t e n t i a l a s s e s s m e n t t e c h n i q u e a n d t h e n r a n d o m l y a s s i g n e d t o r e q u l a r gr-ades o r s p e c i a l c l a s s e s , B u d o f f a n d G o t t l i e b (1976 ) f o u n d f u r t h e r s u p p o r t f o r t h e u s e o f t h e l e a r n i n g p o t e n t i a l a s s e s s m e n t t e c h n i q u e . I t was r e p o r t e d t h a t c h i l d r e n c l a s s i f i e d a s h i g h a b l e b y t h e l e a r n i n g p o t e n t i a l p r o c e d u r e p e r f o r m e d more c o m p e t e n t l y a c a d e m i c a l l y t h a n low a b l e c l a s s i f i e d s t u d e n t s , r e g a r d l e s s o f p l a c e m e n t . F e u e r s t e i n (1979) has d e v e l o p e d a t e c h n i q u e w h i c h he c a l l s L e a r n i n g P o t e n t i a l A s s e s s m e n t D e v i c e (LPAD) t h a t he c l a i m s a l s o m e a s u r e s a p e r s o n ' s l e a r n i n g p o t e n t i a l . T h i s i s s i m i l a r t o t h e t e c h n i q u e s o f B u d o f f a n d h i s a s s o c i a t e s i n t h a t i t i s a t e s t - t e a c h - t e s t p r o c e d u r e i n w h i c h t h e e x a m i n e r a n d e x a m i n e e . 26 i n t e r a c t s o a s t o b e t t e r e l i c i t c h a n g e i n t h e e x a m i n e e . F e u e r s t e i n a d m i t s t h i s c o n t a m i n a t e s t h e r e l i a b i l i t y o f s t a n d a r d p s y c h o m e t r i c m e a s u r e s , b u t c l a i m s t h a t h i s s y s t e m m o d e l s an i d e a l l e a r n i n g s i t u a t i o n . T h i s he c l a i m s , p r o v i d e s a framework w i t h i n w h i c h t h e o p p o r t u n i t y f o r s u c e s s i s m a x i m i z e d , m a k i n g i t p o s s i b l e t o a c q u i r e i n s i g h t s i n t o a n i n d i v i d u a l ' s l e a r n i n g p o t e n t i a l t h a t w o u l d f a i l t o s u r f a c e i n a s t a n d a r d i z e d t e s t i n g s i t u a t i o n . Change p r o d u c e d d u r i n g t h e c o u r s e o f a s s e s s m e n t i s i n t e r p r e t e d a s e v i d e n c e o f t h e i n d i v i d u a l 's p o t e n t i a l m o d i f i a b i l i t y . One o f t h e s t u d i e s w h i c h F e u e r s t e i n a n d h i s a s s o c i a t e s (1981) r e p o r t e d was t o a s c e r t a i n t o w h a t e x t e n t c o n v e n t i o n a l t e s t s a c c u r a t e l y r e f l e c t e d t h e a b i l i t i e s o f 34 e i g h t h g r a d e s u b j e c t s f r o m a r u r a l s c h o o l d e f i n e d by t h e I s r a e l i M i n i s t r y o f E d u c a t i o n a s d i s a d v a n t a g e d . The s u b j e c t s were f i r s t t e s t e d on a s t a n d a r d i z e d a d u l t s e r i e s o f t h e R a v e n ' s M a t r i c e s , and t h e n g i v e n a g r o u p a d m i n i s t r a t i o n o f LPAD. Th e r e s u l t s f o r t h e R a v e n s M a t r i c e s (M = 2 9 . 5 , SD = 8.8) p l a c e d t h e s u b j e c t s i n a w e l l b e l o w a v e r a g e c a t e g o r y , t h u s n o t e l i g i b l e f o r a c a d e m i c H i g h S c h o o l . T h e r e s u l t s f r o m t h e LPAD s u g g e s t e d t h a t t h e Raven t e s t s e v e r e l y u n d e r e s t i m a t e d a b i l i t y . I n a s e c o n d s t u d y F e u e r s t e i n e t a l . (1981) i n v e s t i g a t e d t o s e e i f t h e l o w p e r f o r m a n c e o f some s t u d e n t s i n c l a s s e s f o r s t u d e n t s o f low a b i l i t y a c c u r a t e l y r e f l e c t e d t h e i r a b i l i t i e s . I n t h i s s t u d y t h e s t u d e n t s f r o m two h i g h f u n c t i o n i n g c l a s s e s a n d two l o w f u n c t i o n i n g c l a s s e s w e r e t e s t e d o n t h e P r i m a r y M e n t a l A b i l i t i e s (PMA) t e s t ( T h u r s t o n e , 1938) a n d t h e LPAD. R e s u l t s s h o w e d t h a t o n t h e PMA t h e l o w f u n c t i o n i n g g r o u p s . 27 s c o r e d l o w e r t h a n t h e h i g h f u n c t i o n i n g g r o u p s , b u t on t h e LPAD t e s t s o n l y t w o o f s i x c o m p a r i s o n s y i e l d e d s i g n i f i c a n t d i f f e r e n c e s . The g r o u p s w e r e t h e n m e r g e d i n t o h e t e r o g e n e o u s c l a s s e s . A f t e r o n e y e a r t h e same t e s t s were r e a d m i n i s t e r e d . A l l g r o u p s i m p r o v e d o n a l l t h e t e s t s . On t h e PMA no s i g n i f i c a n t d i f f e r e n c e s were f o u n d b e t w e e n a n y o f t h e g r o u p s . Some s t u d e n t s f r o m t h e h i g h p e r f o r m i n g c l a s s e s who were n o t i n c l u d e d i n t h e m i x e d c l a s s e s p r o v i d e d a c o n t r o l a g a i n s t t h e p o s s i b i l i t y t h a t h i g h p e r f o r m i n g s t u d e n t s came down t o t h e l e v e l o f t h e low p e r f o r m i n g o n e s . A l t h o u g h r e s e a r c h i n l e a r n i n g p o t e n t i a l has b e e n l i m i t e d , t h e s e s t u d i e s , a n d e s p e c i a l l y t h o s e o f B u d o f f a n d h i s a s s o c i a t e s w h i c h u s e d l a r g e numbers o f s u b j e c t s , p r o v i d e some e v i d e n c e t h a t a l e a r n i n g p o t e n t i a l a s s e s s m e n t b a s e d o n a t e s t - r e t e s t t e c h n i q u e i s a v i a b l e p r o c e d u r e f o r m e a s u r i n g t h e l e a r n i n g a b i l i t i e s o f s t u d e n t s . In summary, s t u d i e s have b e e n r e v i e w e d i n t h i s s e c t i o n i n w h i c h r e s e a r c h e r s have e x a m i n e d s e v e r a l e x p e r i m e n t a l p r o c e d u r e s f o r m e a s u r i n g l e a r n i n g p o t e n t i a l . T h e s e p r o c e d u r e s a r e b a s e d on a t e s t - t r a i n - r e t e s t method w h i c h u s e s t h e g a i n on t h e r e t e s t o f a c e r t a i n t e s t a s a measure o f l e a r n i n g p o t e n t i a l . A l t h o u g h e x p e r i m e n t a l and l i m i t e d i n number, t h e s t u d i e s were r e l i a b l e and i n d i c a t e t h i s p r o c e d u r e may have some v a l i d i t y i n m e a s u r i n g l e a r n i n g p o t e n t i a l . They a r e i m p o r t a n t t o t h e p r e s e n t s t u d y as t h e y i n d i c a t e one way t h a t t h e WISC-R C o d i n g s u b t e s t m i g h t be u s e d t o s e e i f t h i s s u b t e s t may m e a s u r e l e a r n i n g p o t e n t i a l . T h e n e x t s e c t i o n w i l l r e v i e w s t u d i e s i n w h i c h t e s t - r e t e s t s t u d i e s o f t h e W e c h s l e r s c a l e s , a n d e s p e c i a l l y t h e C o d i n g . 28 s u b t e s t h a v e been c a r r i e d o u t . T e s t - R e t e s t S t u d i e s o f t h e W e c h s l e r S c a l e s . One o f t h e e a r l i e r t e s t - r e t e s t s t u d i e s o n t h e W e c h s l e r s c a l e s was t h e r e l i a b i l i t y s t u d y b y D e r n e r e t a l . ( 1 9 5 0 ) , o n t h e W e c h s 1 e r - B e 1 1 v u e s c a l e . T h e p u r p o s e o f t h i s s t u d y was t o d e t e r m i n e s u b t e s t r e l i a b i l i t y a n d t h e e f f e c t on r e l i a b i l i t y o f v a r y i n g l e n g t h s o f t i m e b e f o r e r e t e s t i n g . T h r e e g r o u p s o f n o r m a l s u b j e c t s w e r e r e t e s t e d . One g r o u p o f 38 s u b j e c t s was r e t e s t e d w i t h a s i x month i n t e r v a l between t e s t s , a n o t h e r g r o u p o f 60 s u b j e c t s was r e t e s t e d w i t h a f o u r week i n t e r v a l , and t h e t h i r d g r o u p o f 60 s u b j e c t s was r e t e s t e d w i t h a o n e w e e k i n t e r v a l b e t w e e n t e s t s . Ages f o r t h e s u b j e c t s r a n g e d f r o m 21.5 t o 49.6 y e a r s and f u l l s c a l e IQ s c o r e s f r o m 110.1 t o 118.5. I t was f o u n d t h a t e v e r y g r o u p mean i n c r e a s e d s i g n i f i c a n t l y - i n t h e r e t e s t . I t was a l s o f o u n d t h a t t h e s i x m o n t h t e s t i n t e r v a l g r o u p i n c r e a s e d l e s s t h a n t h e o t h e r two g r o u p s a n d t h e f o u r w e e k i n t e r v a l ' g r o u p i n c r e a s e d l e s s t h a n t h e o n e week t e s t i n t e r v a l g r o u p . A t - t e s t f o r t h e s i g n i f i c a n c e o f t h e d i f f e r e n c e between c o e f f i c i e n t s o f r e l a t i v e v a r i a t i o n , w h i c h d e c r e a s e d t h e s i z e o f t h e s t a n d a r d e r r o r s o a s t o make s m a l l d i f f e r e n c e s s i g n i f i c a n t , i n d i c a t e d t h a t e v e r y s u b t e s t showed a s i g n i f i c a n t d i f f e r e n c e on t h e r e t e s t . T h e m o s t s t a b l e s u b t e s t s w e r e ; V o c a b u l a r y , I n f o r m a t i o n , B l o c k D e s i g n , P i c t u r e C o m p l e t i o n and D i g i t Symbol ( C o d i n g ) . S i n c e t h e r e l i a b i l i t y c o e f f i c i e n t , as d e t e r m i n e d by r e t e s t i n g , shows t o what d e g r e e a s u b j e c t ' s r e l a t i v e p o s i t i o n i n a s a m p l e g r o u p r e m a i n s t h e same o v e r t i m e , t h e c o n s i s t e n c y o f t h e p r a c t i c e e f f e c t c a n be n o t e d , a s p r a c t i c e e f f e c t may . 29 c a u s e t h e s c o r e on t h e r e t e s t t o be h i g h e r t h a n o n t h e f i r s t a d m i n i s t r a t i o n . T h e r e f o r e t h i s s t u d y seems t o i n d i c a t e t h a t a s D i g i t S y m b o l ( C o d i n g ) has a h i g h t e s t - r e t e s t r e l i a b i l i t y , ( r = . 78 - . 85 o v e r 1 week a n d 6 m o n t h s ) , i t s p r a c t i c e e f f e c t w i l l b e c o n s i s t e n t o v e r t i m e . F u r t h e r m o r e , i t a l s o s e e m s t o i n d i c a t e t h a t t h e p r a c t i c e e f f e c t w i l l b e l e s s e n e d a s t h e i n t e r v a l between r e t e s t s i s i n c r e a s e d . L a z a r u s a n d E r i c k s o n ( 1 9 5 2 ) c o m p a r e d h i g h a n d l o w a c h i e v e r s on a t e s t - r e t e s t s t u d y o f t h e WAIS. R e s u l t s o f t h e i r s t u d y i n d i c a t e d t h a t h i g h a c h i e v e r s i m p r o v e d a n d low a c h i e v e r s d i d m o r e p o o r l y o n t h e s e c o n d a d m i n i s t r a t i o n o f t h e D i g i t Symbol ( C o d i n g ) s u b t e s t . I n a s t u d y by I r w i n ( 1 9 6 6 ) t h e r e l i a b i l i t y o f t h e WISC a t two s e l e c t e d age l e v e l s was i n v e s t i g a t e d . S i x t y s u b j e c t s o f c o m p a r a b l e i n t e l l i g e n c e , a g e d 5-7 t o 6-6 y e a r s o r 10-7 t o 11-7, w e r e r e t e s t e d a t 28 o r 35 d a y s r e s p e c t i v e l y . S p l i t - h a l f r e l i a b i l i t y c o e f f i c i e n t s i n d i c a t e d a g e n e r a l t r e n d f o r a n i n c r e a s e i n r e l i a b i l i t y f r o m t h e s i x y e a r t o t h e e l e v e n y e a r a g e g r o u p . T h e h i g h r e l i a b i l i t y f o u n d f o r t h e C o d i n g s u b t e s t ( r . = .67 and .88 r e s p e c t i v e l y ) a d d e d f u r t h e r s u p p o r t t o t h e e a r l i e r f i n d i n g o f D e r n e r e t a l . ( 1 9 5 0 ) . Q u e r e s h i (1968) r e t e s t e d 328 s u b j e c t s , a t f i v e a g e l e v e l s b etween f i v e a nd f o u r t e e n y e a r s , o v e r a t h r e e month p e r i o d w i t h t h e W I S C . A n a n a l y s i s o f v a r i a n c e r e v e a l e d t h a t p r a c t i c e e f f e c t s f o r C o d i n g w e r e s i g n i f i c a n t a t a l l age b r a c k e t s (p < .001) . A d d i t i o n a l s u p p o r t f o r e a r l i e r s t u d i e s was t h e f i n d i n g t h a t t h e I n f o r m a t i o n , V o c a b u l a r y , B l o c k D e s i g n a n d C o d i n g s u b t e s t s y i e l d e d t h e m o s t s t a b l e s c o r e s o n t e s t - r e t e s t . 30 c o r r e l a t i o n s . Two f u r t h e r s t u d i e s w h i c h f o u n d t h e C o d i n g s u b t e s t t o be one o f t h e most s t a b l e o f t h e W e c h s l e r s c a l e s ' s u b t e s t s w e r e t h o s e o f M a t a r a z z o e t a l . ( 1 973 ), a n d Tuma a n d A p p e l b a u m (1980 ) . T h e s t u d y by M a t a r r a z z o f o u n d C o d i n g t o h a v e t h e h i g h e s t r e l i a b i l i t y o f t h e WAIS s u b t e s t s ( r . = .87) f o r n o r m a l men o v e r a t h r e e t o f i v e month r e t e s t p e r i o d . F u r t h e r m o r e , t h e mean g a i n f o r t h i s s u b t e s t was f o u n d t o be one p o i n t w i t h no r e l a t i o n s h i p b e i n g n o t e d b e t w e e n i n i t i a l IQ and s i z e o f g a i n . I n Tuma and A p p e l b a u m s ' ( 1 9 8 0 ) s t u d y B l o c k D e s i g n a n d C o d i n g w e r e f o u n d t o b e t h e m o s t s t a b l e o f t h e WISC-R P e r f o r m a n c e s c a l e s u b t e s t s among n o r m a l c h i l d r e n o v e r a s i x month r e t e s t p e r i o d ( r = .78 f o r b o t h ) . A n e t g a i n f o r C o d i n g was f o u n d t o be t h e l a r g e s t f o r a l l o f t h e s u b t e s t s e x c e p t f o r P i c t u r e C o m p l e t i o n a n d A r r a n g e m e n t . H o w e v e r b o t h t h e P i c t u r e C o m p l e t i o n a n d A r r a n g e m e n t s u b t e s t s w e r e a l s o f o u n d t o be t h e most u n s t a b l e ( r = .65 and .54 r e s p e c t i v e l y ) . I n t e s t - r e t e s t r e l i a b i l i t y s t u d i e s among p o p u l a t i o n s w i t h l e a r n i n g p r o b l e m s t h e C o d i n g s u b t e s t was u s u a l l y f o u n d t o be v e r y r e l i a b l e b u t , a n d i n c o n t r a s t t o s t u d i e s w i t h n o r m a l c h i l d r e n , v e r y l i t t l e g a i n was e x h i b i t e d o n t h e r e t e s t . I n s t u d i e s by G i r o n d a ( 1 9 7 7 ) , a n d C a t r o n and C a t r o n ( 1 9 7 7 ) , where EMR c h i l d r e n ' s WISC-R s c o r e s w e r e c o m p a r e d w i t h p r e v i o u s l y a d m i n i s t e r e d WISC s c o r e s o v e r a t h r e e y e a r t i m e i n t e r v a l t h e r e was g e n e r a l l y o v e r a o n e p o i n t l o s s f o r t h e C o d i n g s u b t e s t . The a u t h o r s a d m i t t h a t t h e r e a s o n f o r a o n e p o i n t l o s s o n t h e C o d i n g r e t e s t may be due t o more s t r i n g e n t norms on t h e r e v i s e d WISC-R m a k i n g i t h a r d e r t o s c o r e a s w e l l on t h e WISC-R as on .31 t h e WISC. T h i s was e v i d e n t n o t o n l y i n t h e C o d i n g s c o r e s b u t , i n b o t h s t u d i e s , t h e r e was a l o s s o n m o s t s u b t e s t s o f t h e WISC-R as w e l l . I n C a t r o n and C a t r o n ' s s t u d y C o d i n g showed t h e g r e a t e s t l o s s o f a l l t h e s u b t e s t s o f t h e WISC-R when compared t o p r e v i o u s l y g i v e n WISC s c o r e s . T h e t i m e i n t e r v a l f o r t h e r e t e s t i n t h i s s t u d y was t h r e e weeks. A s t u d y b y S o l l y ( 1 9 7 7 ) c o m p a r e d t h e WISC a n d WISC-R s c o r e s o f g i f t e d a n d EMR c h i l d r e n . T w e l v e g i f t e d and t w e l v e EMR c h i l d r e n r a n d o m l y s e l e c t e d w e r e a d m i n i s t e r e d t h e WISC and WISC-R i n c o u n t e r b a l a n c e d o r d e r , t o m i n i m i z e p r a c t i c e e f f e c t , w i t h i n 72 h o u r s o f e a c h o t h e r . U s i n g a 2 x 2 x 2 r e p e a t e d m e a s u r e s a n a l y s i s t h e a u t h o r f o u n d t h a t mean WISC s c o r e s were s i g n i f i c a n t l y h i g h e r t h a n WISC-R s c o r e s i n b o t h t h e g i f t e d a n d r e t a r d e d g r o u p s (p < .001 ) . However t h e C o d i n g s u b t e s t seemed t o show l e a s t p r a c t i c e e f f e c t f o r s u b t e s t s i n t h e d i s a b l e d g r o u p . Lombard a n d R i e d e l (1978) compared t h e o l d (WISC) a n d new ( W I S C - R ) f o r m a t s o f t h e C o d i n g B s u b t e s t d u r i n g a f a c t o r a n a l y t i c s t u d y o f t h e WISC-R among r u r a l c h i l d r e n w i t h l e a r n i n g p r o b l e m s . S u b j e c t s w e r e g i v e n t h e e n t i r e WISC-R w i t h some r e c e i v i n g t h e o l d (WISC) f o r m o f t h e C o d i n g s u b t e s t e a r l y i n t h e t e s t i n g a n d t h e new (WISC-R) f o r m a t t h e e n d , w h i l e t h e o t h e r s u b j e c t s r e c e i v e d t h e two t e s t s i n t h e o p p o s i t e o r d e r . No o r d e r e f f e c t s were f o u n d , i n d i c a t i n g t h a t w h a t e v e r p r a c t i c e e f f e c t e x i s t e d was t o o s m a l l t o m e a s u r e . The a u t h o r s f o u n d t h i s t o be a c o n c e r n b e c a u s e t h e y h a d f o u n d a s t r o n g a n d s i g n i f i c a n t p r a c t i c e e f f e c t w i t h c o l l e g e age s u b j e c t s . S m i t h (19 7 8) a d m i n i s t e r e d t h e WISC-R t o 161 l e a r n i n g . 3 2 d i s a b l e d c h i l d r e n a n d t h e n r e a d m i n i s t e r e d i t e i g h t m o n t h s l a t e r . A c o m p a r i s o n o f t h e t e s t - r e t e s t r e s u l t s f o u n d t h e p r o f i l e s a l m o s t i d e n t i c a l w i t h a v e r y s m a l l i n c r e a s e i n s c o r e s on. t h e s e c o n d a d m i n i s t r a t i o n . T h e o n l y e x c e p t i o n was v o c a b u l a r y w h i c h s h o w e d a , d e c r e a s e . T h e mean g a i n o n t h e C o d i n g s u b t e s t was .4 o f a s c a l e d s c o r e p o i n t . A l o n g w i t h B l o c k D e s i g n ( g a i n = .1) C o d i n g was l e a s t , s u s c e p t i b l e t o t h e i n f l u e n c e o f p r a c t i c e . T h e r e l a t i v e m a g n i t u d e s o f t h e mean s u b t e s t c h a n g e s i n t h i s s t u d y c o r r e s p o n d e d c l o s e l y t o t h o s e r e p o r t e d by W e c h s l e r ( 1 9 7 4 ) . T h i s s e c t i o n r e v i e w e d s t u d i e s d e a l i n g w i t h t e s t - r e t e s t s t u d i e s o f t h e WISC a n d WISC-R C o d i n g s u b t e s t . T h e s e s t u d i e s i n d i c a t e d t h a t n o r m a l o r g i f t e d s u b j e c t s g e n e r a l l y i m p r o v e d s i g n i f i c a n t l y on a r e t e s t w h i l e l e a r n i n g d i s a b l e d s u b j e c t s d i d n o t . F u r t h e r m o r e , t h e s e s t u d i e s i n d i c a t e d t h a t t h e i n c r e a s e on a r e t e s t o f t h i s s u b t e s t was g r e a t e r o v e r a s h o r t t i m e i n t e r v a l t h a n o v e r a l o n g e r p e r i o d o f t i m e . H o wever t h i s s u b t e s t was a l s o f o u n d t o be r e l i a b l e w i t h t h e i n c r e a s e on t h e r e t e s t b e i n g c o n s i s t e n t o v e r t i m e . T h e s e s t u d i e s add f u r t h e r s u p p o r t t o t h e i d e a t h a t t h e C o d i n g s u b t e s t o f t h e WISC-R m i g h t b e u s e d a s a m e a s u r e o f l e a r n i n g p o t e n t i a l i f t h e t e s t - r e t e s t s c o r e s a r e u s e d t o d i f f e r e n t i a t e b e t w e e n n o r m a l a n d l e a r n i n g d i s a b l e d s u b j e c t s . Summary T h i s r e v i e w o f t h e l i t e r a t u r e e x a mined s t u d i e s w h i c h d e a l t w i t h t h e p r o b l e m s o f t h e a s s e s s m e n t o f l e a r n i n g p o t e n t i a l . W h i l e some i n v e s t i g a t o r s c l a i m e d t h a t s t a n d a r d i z e d t e s t s may . 33 n o t be a v a l i d m e a s u r e o f a c h i l d ' s i n t e l l e c t u a l p o t e n t i a l , o t h e r s c l a i m e d t h a t some s u b t e s t s o f t h e WISC-R may be t h o u g h t o f a s l e a r n i n g t a s k s . One o f t h e s e i s C o d i n g w h i c h t h e y c l a i m may be a t e s t o f a s u b j e c t ' s a b i l i t y t o a c q u i r e new l e a r n i n g . I n t h e n e x t s e c t i o n o f t h i s r e v i e w f a c t o r a n a l y t i c s t u d i e s o f t h e WISC a n d WISC-R w e r e e x a m i n e d . I t was c o n c l u d e d f r o m t h e s e s t u d i e s t h a t l e a r n i n g d i s a b l e d s u b j e c t s s e e m e d t o h a v e t h e m o s t d i f f i c u l t y w i t h t h e A r i t h m e t i c , D i g i t Span and C o d i n g s u b t e s t s . F u r t h e r s t u d i e s i n t h i s a r e a i n d i c a t e d t h a t t h e C o d i n g s u b t e s t m e a s u r e s s o m e t h i n g d i f f e r e n t f r o m t h e o t h e r s u b t e s t s a n d p e r h a p s e v e n f r o m t h e g e n e r a l IQ s c o r e s . C o d i n g a l s o seemed t o i d e n t i f y l e a r n i n g d i s a b l e d c h i l d r e n . A l t h o u g h f a c t o r a n a l y t i c s t u d i e s p u t t h e C o d i n g s u b t e s t i n a c a t e g o r y l a b e l l e d \" D i s t r a c t i b i l i t y , \" s t u d i e s r e v i e w e d seemed t o i n d i c a t e t h a t C o d i n g d o e s n o t m e a s u r e d i s t r a c t i b l e b e h a v i o r t o a n y s i g n i f i c a n t d e g r e e . R e s e a r c h e r s i n d i c a t e d t h a t i n f a c t i t may measure some c o g n i t i v e a b i l i t y , and a l t h o u g h some s u g g e s t i o n s o f w h i c h c o g n i t i v e f u n c t i o n s i t may m e a s u r e w e r e l i s t e d , no s t u d i e s w e r e r e p o r t e d w h i c h p r e c i s e l y d e f i n e d w h i c h o n e s i t r e a l l y m e a s u r e s . The n e x t s e c t i o n o f t h i s r e v i e w a n a l y z e d s t u d i e s by some r e s e a r c h e r s w h i c h a d v o c a t e d t h e u s e o f a t e s t - t r a i n - r e t e s t p r o c e d u r e t o m e a s u r e l e a r n i n g p o t e n t i a l . A l t h o u g h t h e s e r e s e a r c h e r s a d m i t t h i s i s a n e x p e r i m e n t a l p r o c e d u r e t h e s e s t u d i e s h a v e g o o d r e l i a b i l i t y a n d i n some c a s e s u s e d l a r g e n u m b e r s o f s u b j e c t s t o p r o v i d e some e v i d e n c e t h a t t h i s p r o c e d u r e may b e a v i a b l e way o f m e a s u r i n g t h e l e a r n i n g p o t e n t i a l o f s t u d e n t s . . 34 T h e l a s t s e c t i o n o f t h i s r e v i e w e x a m i n e d t e s t - r e t e s t s t u d i e s o f t h e W e c h s l e r I n t e l l i g e n c e S c a l e s . I t was f o u n d t h a t g e n e r a l l y n o r m a l a n d g i f t e d s u b j e c t s o f a l l a g e s i m p r o v e d s i g n i f i c a n t l y o n t h e r e t e s t o f m o s t o f t h e WISC a n d WISC-R s u b t e s t s , a n d s p e c i f i c a l l y t h e C o d i n g s u b t e s t . L e a r n i n g d i s a b l e d s u b j e c t s g e n e r a l l y d i d n o t i m p r o v e s i g n i f i c a n t l y and i n some c a s e s d i d w o r s e o n t h e r e t e s t . T h i s e f f e c t was c o n s i s t e n t o v e r t i m e f o r b o t h t h e n o r m a l and l e a r n i n g d i s a b l e d s u b j e c t s w i t h a g r e a t e r i n c r e a s e o v e r t h e s h o r t e r r e t e s t p e r i o d . C h a p t e r 3 w i l l o u t l i n e t h e m e t h o d s and p r o c e d u r e s o f t h i s s t u d y . The s e l e c t i o n o f s u b j e c t s w i l l be e x p l a i n e d a s w e l l a s a d e s c r i p t i o n o f t h e t e s t s u s e d . L a s t l y t h e p r o c e d u r e s f o r a n a l y z i n g t h e d a t a w i l l be d e s c r i b e d . \u00E2\u0080\u00A2 3 5 CHAPTER I I I Method S u b j e c t s T h e p u r p o s e o f t h i s s t u d y was t o compare two s a m p l e s , one c o m p r i s e d o f a l e a r n i n g d i s a b l e d g r o u p o f s t u d e n t s , a n d t h e o t h e r o f n o r m a l s t u d e n t s , i n t e r m s o f t h e i r p e r f o r m a n c e o n a t e s t - r e t e s t a d m i n i s t r a t i o n o f t h e WISC-R C o d i n g s u b t e s t . The sa m p l e s f o r t h i s s t u d y w e r e d r a w n f r o m two s c h o o l d i s t r i c t s ; C h i l l i w a c k S c h o o l D i s t r i c t a n d K a m l o o p s S c h o o l D i s t r i c t . L e a r n i n g d i s a b l e d s t u d e n t s w e r e d r a w n f r o m t h e r e g i o n a l e d u c a t i o n c e n t e r s i n e a c h d i s t r i c t . The C h i l l i w a c k s c h o o l f r o m w h i c h t h e n o r m a l s a m p l e was d r a w n was l o c a t e d i n a r u r a l s e t t i n g , i t s p o p u l a t i o n c o m p r i s e d b a s i c a l l y o f r u r a l c h i l d r e n o f l o w e r s o c i o - e c o n o m i c s t a t u s ( S E S ) . The Kamloops s c h o o l f r o m w h i c h t h e n o r m a l s a m p l e was d r a w n was i n a s u b u r b a n s e t t i n g , i t s p o p u l a t i o n c o m p r i s e d m a i n l y o f u r b a n c h i l d r e n f r o m m i d d l e t o u p p e r m i d d l e c l a s s b a c k g r o u n d s . A f t e r c o n s u l t a t i o n w i t h t h e c h i l d r e n ' s t e a c h e r s i n b o t h d i s t r i c t s , i t was assumed, t h a t t h e SES o f t h e n o r m a l s a m p l e g r o u p was s i m i l a r t o t h a t o f t h e l e a r n i n g d i s a b l e d g r o u p . S t u d e n t s f r o m g r a d e s t w o t o s i x w e r e s e l e c t e d f o r t h e s a m p l e a s t h i s was t h e same a g e u s e d i n o t h e r s t u d i e s on p r a c t i c e e f f e c t s o f t h e WISC-R (Tuma & A p p e l b a u m 1980, S m i t h 1 9 7 8 , L o m b a r d & R e i d e l 1 9 7 8 ) . The number o f s u b j e c t s f o r e a c h g r o u p was d e t e r m i n e d by t h e number o f s t u d e n t s a v a i l a b l e f r o m t h e r e g i o n a l l e a r n i n g d i s a b l e d e d u c a t i o n c e n t e r s . T h u s f o r e a c h l e a r n i n g d i s a b l e d s t u d e n t s e l e c t e d f r o m t h e r e g i o n a l c e n t e r , one c h i l d was r a n d o m l y s e l e c t e d f r o m t h e p u b l i c s c h o o l . 36 f o r i n c l u s i o n i n t h e n o r m a l g r o u p . T h e s e l e c t i o n o f p u b l i c s c h o o l s was d i c t a t e d by t h e s c h o o l d i s t r i c t a d m i n i s t r a t i o n . N o r m a l G r o u p s . To q u a l i f y , f o r o n e o f t h e two g r o u p s o f n o r m a l s t u d e n t s , c h i l d r e n were t o : -be i n g r a d e s two t o s i x -have no known l e a r n i n g d i s a b i l i t y -be p e r f o r m i n g a t a n a d e q u a t e l e v e l i n a l l s u b j e c t s a s d e t e r m i n e d by t h e i r t e a c h e r ; and -have a l e a r n i n g p o t e n t i a l i n t h e n o r m a l t o a b o v e n o r m a l r a n g e a s d e t e r m i n e d by a WISC-R IQ s c o r e . M o s t o f t h e c h i l d r e n f r o m t h e r e g u l a r c l a s s r o o m s d i d n o t h a v e a WISC-R I Q s c o r e a v a i l a b l e . I n i t s p l a c e t h e i r B.C.Q.U.I.E.T. s c o r e s w e r e i n t e r p r e t e d s o t h a t i f a v e r a g e t o a b o v e s c o r e s w e r e o b t a i n e d i n a l l f o u r s u b t e s t s , t h i s w o u l d i n d i c a t e a n o r m a l IQ r a n g e ( W o r m e l i , 1 9 8 2 ) . D i s a b l e d G r o u p s . To q u a l i f y f o r one o f t h e two l e a r n i n g d i s a b l e d g r o u p s c h i l d r e n were t o : -be i n g r a d e s two t o s i x -have b e e n r e f e r r e d t o a r e g i o n a l e d u c a t i o n c e n t e r b e c a u s e t h e y were s u s p e c t e d o f h a v i n g a l e a r n i n g d i s a b i l i t y -be p e r f o r m i n g one o r more y e a r s below g r a d e l e v e l o n o n e o r more a c a d e m i c s u b j e c t s - h a v e a l e a r n i n g p o t e n t i a l i n t h e n o r m a l t o ab o v e n o r m a l r a n g e as d e t e r m i n e d by a WISC-R IQ s c o r e . I n s t r u m e n t s The i n s t r u m e n t s u s e d i n t h i s s t u d y were t h e C o d i n g S u b t e s t o f t h e WISC-R ( W e c h s l e r , 1 9 7 4 ) , a n d t h e B . C . Q . U . I . E . T . ( W o r m e l i , 1 9 8 2 ) . . 37 C o d i n g . The C o d i n g s u b t e s t o f t h e WISC-R ( W e c h s l e r 1974) i s composed o f two p a r t s . C o d i n g A i s a d m i n i s t e r e d t o c h i l d r e n u n d e r 8 y e a r s o f a g e . I t c o n s i s t s o f f i v e s h a p e s : a s t a r , c i r c l e , t r i a n g l e , c r o s s , a n d s q u a r e . E a c h s h a p e h a s a d i f f e r e n t m a r k i n i t . T h e f i v e s h a p e s a r e f o l l o w e d by f i v e p r a c t i c e s h a p e s a n d t h e f o r t y - t h r e e s h a p e s o f t h e s u b t e s t p r o p e r . The c h i l d i s r e q u i r e d t o p l a c e i n e a c h o f t h e s h a p e s o f t h e s u b t e s t t h e mark t h a t i s f o u n d i n t h e i n i t i a l f i v e s a mple s h a p e s . C o d i n g B, w h i c h i s a d m i n i s t e r e d t o c h i l d r e n 8 y e a r s o l d and o v e r , c o n s i s t s o f b o x e s c o n t a i n i n g t h e numbers 1 t h r o u g h 9 a n d a s y m b o l below e a c h number. The c h i l d i s r e q u i r e d t o copy t h e symbol a s s o c i a t e d w i t h t h e a p p r o p r i a t e number i n an empty b o x u n d e r t h e 9 3 b o x e s o f n u m b e r s t h a t make u p t h e s u b t e s t p r o p e r . The t i m e l i m i t i s 120 s e c o n d s f o r b o t h C o d i n g A and B. A c c o r d i n g t o r e s e a r c h C o d i n g r e q u i r e s t h e a b i l i t y t o l e a r n a n u n f a m i l i a r t a s k , i n v o l v e s s p e e d a n d a c c u r a c y o f e y e hand c o o r d i n a t i o n , a t t e n t i o n a l s k i l l s , s h o r t t e r m memory a n d m o t i v a t i o n ( S a t t l e r 1 9 8 2 , p . 1 8 6 ) . C o d i n g i s a s o m e w h a t r e l i a b l e s u b t e s t o f t h e WISC-R ( r = . 7 2 ) , b u t h a s a l o w c o r r e l a t i o n w i t h t h e F u l l S c a l e WISC-R IQ ( r = .38) w i t h t h e P e r f o r m a n c e S c a l e ( r = .33) a n d t h e V e r b a l S c a l e ( r = .36) ( S a t t l e r 1 9 8 2 ) . Th e l o w c o r r e l a t i o n o f C o d i n g w i t h t h e o t h e r s u b t e s t s o f t h e WISC-R, p l u s t h e f a c t t h a t o n F a c t o r A n a l y t i c s t u d i e s C o d i n g d o e s n o t f i t w e l l i n t o any o f t h e g i v e n f a c t o r s (Kaufman 19 7 5 ) s u g g e s t s t h a t t h e C o d i n g s u b t e s t may b e m e a s u r i n g s o m e t h i n g o t h e r t h a n what i s m e a s u r e d by t h e WISC-R. T h i s has . 38 l e d some r e s e a r c h e r s t o s u g g e s t t h a t i t may h a v e s i n g u l a r d i a g n o s t i c i m p o r t a n c e ( T a b a c h n i c k 1 9 79). B.C.Q.U.I.E.T. The B.C. Q u i c k I n d i v i d u a l E d u c a t i o n a l T e s t ( W o r m e l i , 1 9 8 2 ) , c o n s i s t s o f f o u r s u b t e s t s w h i c h may be a d m i n i s t e r e d t o g e t h e r o r s e p a r a t e l y . The s u b t e s t s a r e d e s i g n e d t o b e u s e d a t t h e e l e m e n t a r y l e v e l ( g r a d e s one t o s e v e n ) , and m e a s u r e s t u d e n t s p r o g r e s s i n S p e l l i n g , A r i t h m e t i c , Word I d e n t i f i c a t i o n a n d P a s s a g e C o m p r e h e n s i o n . T h e i t e m s i n t h e s u b t e s t s a r e a l l s e l e c t e d f r o m B.C. M i n i s t r y o f E d u c a t i o n p r e s c r i b e d t e x t b o o k s , o r r e p r e s e n t l e a r n i n g o u t c o m e s o f t h e M i n i s t r y ' s C u r r i c u l u m G u i d e s . E a c h o f t h e s u b t e s t s a r e a d m i n i s t e r e d i n d i v i d u a l l y t o s t u d e n t s a n d t a k e a b o u t f i f t e e n m i n u t e s t o c o m p l e t e . A f t e r a s t u d e n t ' s raw s c o r e i s d e t e r m i n e d t h e s e a r e t h e n c o n v e r t e d i n t o Normal C u r v e E q u i v a l e n t s (NCE's) w h i c h have a r a n g e o f 1 t o 100 and a mean o f 50. S i n c e t h e NCE i s a s t a n d a r d s c o r e i t c a n be r e a d i l y u s e d i n s t a t i s t i c a l a n a l y s i s . The a u t h o r ( W o r m e l i , 1982) c l a i m s t h a t t h e B.C.Q.U.I.E.T. c a n be u s e d as a s c r e e n i n g d e v i c e t o i d e n t i f y s t u d e n t s who a r e e l i g i b l e f o r r e f e r r a l t o r e m e d i a l s e r v i c e s . A v a l i d a t i o n s t u d y i s shown w h i c h d e m o n s t r a t e s t h a t t h e W o r d I d e n t i f i c a t i o n s u b t e s t i d e n t i f i e d b e t t e r t h a n 90% o f t h o s e g r a d e 3 s t u d e n t s r e c e i v i n g r e m e d i a l i n s t r u c t i o n i n r e a d i n g . F o r t h e S p e l l i n g and A r i t h m e t i c s u b t e s t s t h i s f i g u r e was 8 5%. F o r g r a d e 7 t h e f i g u r e s were 9 3 % , 92% a n d 6 3 % r e s p e c t i v e l y . When o n e t a k e s i n t o c o n s i d e r a t i o n t h e w i d e l y d i f f e r i n g s t a n d a r d s b y w h i c h l e a r n i n g d i s a b l e d c h i l d r e n a r e i d e n t i f i e d t h r o u g h o u t t h e P r o v i n c e t h i s t e s t seems t o h a v e e x c e l l e n t r e l i a b i l i t y i n .39 i d e n t i f y i n g l e a r n i n g d i s a b l e d p u p i l s . T h e B.C.Q.U.I.E.T. was normed on a p p r o x i m a t e l y 150 p u p i l s a t e a c h o f t h e s e v e n e l e m e n t a r y g r a d e l e v e l s . I n t e r n a l r e l i a b i l i t y i s good f o r a l l s u b t e s t s i n a l l g r a d e l e v e l s ( r = .75 t o . 9 6 ) . T h e t e s t ' s v a l i d i t y f o r m e a s u r i n g t h e a c a d e m i c l e a r n i n g o f B r i t i s h C o l u m b i a s t u d e n t s i s e x c e l l e n t as t h e t e s t i s b a s e d on m a t e r i a l s and c u r r i c u l a u s e d i n B r i t i s h C o l u m b i a s c h o o l s . P r o c e d u r e N o r m a l g r o u p . E a c h o f t h e s u b j e c t s w a s t e s t e d i n d i v i d u a l l y . T h e s u b j e c t s i n t h e n o r m a l g r o u p s w e r e f i r s t a d m i n i s t e r e d t h e C o d i n g s u b t e s t o f t h e WISC-R, f o l l o w e d i m m e d i a t e l y b y t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . S u b j e c t s w e r e t h e n t o l d t h e y w o u l d be g i v e n one o f t h e t e s t s a g a i n , as a c h e c k - u p . S u b j e c t s w e r e t e s t e d i n t h e a f t e r n o o n w i t h t h e C o d i n g r e t e s t w r i t t e n t h e n e x t m o r n i n g . A l l t e s t s w e r e a d m i n i s t e r e d b y t h e a u t h o r a c c o r d i n g t o s t a n d a r d i z e d p r o c e d u r e f o l l o w i n g a l l i n s t r u c t i o n s i n t h e a p p r o p r i a t e m a n u a l. L e a r n i n g d i s a b l e d g r o u p . T h e s u b j e c t s i n t h e l e a r n i n g d i s a b l e d g r o u p s were n o t a d m i n i s t e r e d t h e B . C . Q . U . I . E . T . , a s a l l h a d b e e n g i v e n t h a t t e s t b e t w e e n o n e t o e i g h t w e e k s e a r l i e r , by l e a r n i n g c e n t e r s t a f f . T h e s e s u b j e c t s were f i r s t g i v e n t h e C o d i n g s u b t e s t i n t h e m o r n i n g w i t h a p r o m i s e t h a t t h e y w o u l d do i t a g a i n l a t e r a s a \" c h e c k . \" E a c h s u b j e c t was t h e n r e a d m i n i s t e r e d t h e t e s t t h e n e x t m o r n i n g . B o t h t h e i n i t i a l t e s t and r e t e s t o f t h e C o d i n g s u b t e s t was a d m i n i s t e r e d by t h e a u t h o r a c c o r d i n g t o p u b l i s h e d s t a n d a r d i z e d p r o c e d u r e s . .40 T e s t i n g o f t h e l e a r n i n g d i s a b l e d and n o r m a l g r o u p s on t h e WISC-R C o d i n g s u b t e s t was d o n e d u r i n g t h e s e c o n d a n d t h i r d weeks o f J u n e . M o t i v a t i o n o f t h e s t u d e n t s i n d o i n g t h e t e s t s was f e l t t o be v e r y good. The s t u d e n t s seemed t o e n j o y g e t t i n g o u t o f t h e r e g u l a r c l a s s f o r a w h i l e a n d s e e m e d t o w a n t t o i m p r e s s t h e t e s t a d m i n i s t r a t o r w i t h what t h e y knew. M o t i v a t i o n on t h e r e t e s t o f t h e C o d i n g s u b t e s t was f e l t t o be e s p e c i a l l y g o o d a s t h e t e s t t o o k o n l y a v e r y s h o r t t i m e t o do a n d some s t u d e n t s seemed t o p e r c e i v e i t as a \"game\" o r \" p u z z l e . \" A n a l y s i s o f t h e D a t a H y p o t h e s e s 1 - 3 . T h e f i r s t t h r e e h y p o t h e s e s , w h i c h q u e s t i o n w h e t h e r t h e r e i s a d i f f e r e n c e b e t w e e n \" n o r m a l \" and \" l e a r n i n g d i s a b l e d \" s u b j e c t s on p r e and p o s t t e s t C o d i n g s c o r e s were a n a l y z e d u s i n g an a p p r o p r i a t e t - t e s t ( F e r g u s o n 1 9 8 1 ) . The t - t e s t was u s e d f o r t h e s e a n a l y s e s b e c a u s e i t assumes n o r m a l i t y o f d i s t r i b u t i o n s i n t h e p o p u l a t i o n s f r o m w h i c h t h e s a m p l e s a r e drawn. F u t h e r m o r e i t assumes t h a t t h e s e p o p u l a t i o n s have e q u a l v a r i a n c e s . S i n c e b o t h t h e C o d i n g s u b t e s t o f t h e WISC-R and t h e B.C.Q.U.I.E.T. u s e q u a s i - i n t e r v a 1 m easurement s c a l e s t h e above a s s u m p t i o n s a r e met i n u s i n g t h e t - t e s t t o t e s t t h e f i r s t t h r e e h y p o t h e s e s . A f u r t h e r r e a s o n f o r s e l e c t i n g t h e t - t e s t was t h a t t h i s t e s t i s q u i t e r o b u s t e v e n f o r v e r y s m a l l s a m p l e s ( F e r g u s o n 1981, p. 1 8 1 ) , a n d i n t h i s s t u d y a r e l a t i v e l y s m a l l number o f s u b j e c t s was a v a i l a b l e . H y p o t h e s i s 4. i s d e s i g n e d t o e x a m i n e w h a t c o r r e l a t i o n s e x i s t between t h e p r e and p o s t t e s t C o d i n g s c o r e s o f t h e WISC-R and t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . T h i s h y p o t h e s i s .41 was a n a l y z e d u s i n g t h e P e a r s o n p r o d u c t - m o m e n t c o r r e l a t i o n c o e f f i c i e n t ( F e r g u s o n , 1 9 8 1 ) . A g a i n , b e c a u s e t h i s s t a t i s t i c i s u s e d w i t h i n t e r v a l - r a t i o d a t a i t was an a p p r o p r i a t e one t o u s e w i t h b o t h t h e WISC-R C o d i n g s u b t e s t a n d t h e B . C . Q . U . I . E . T . w h o s e s c a l e s a r e m e a s u r e d i n a q u a s i - i n t e r v a l , s t a n d a r d s c o r e f o r m . T h e r e s u l t s o b t a i n e d b y t h i s s t a t i s t i c m u s t b e i n t e r p r e t e d w i t h c a u t i o n s i n c e i t i s b e l i e v e d t h a t t h e N i n t h i s s t a t i s t i c s h o u l d be 30 o r more ( G l a s s & S t a n l e y , 1970) and i n t h i s s t u d y t h e N i n t h e g r o u p s was l e s s (17 a n d 2 1 ) . However when t h e P e a r s o n c o r r e l a t i o n c o e f f i c i e n t s t a t i s t i c was p e r f o r m e d o n t h e WISC-R a n d B . C . Q . U . I . E . T s c o r e s o f t h e c o m b i n e d l e a r n i n g d i s a b l e d a n d n o r m a l g r o u p , t h e t o t a l N e x c e e d e d 30 a n d t h u s t h i s s t a t i s t i c c a n be i n t e r p r e t e d w i t h c o n f i d e n c e . H y p o t h e s i s 5 . i s c o n c e r n e d w i t h d i f f e r e n c e s b e t w e e n \" n o r m a l \" a n d \" l e a r n i n g d i s a b l e d \" g r o u p s as a f u n c t i o n o f e a c h o f t h e i r WISC-R C o d i n g a n d B.C.Q.U.I.E.T. s u b t e s t s c o r e s . T h i s was a n a l y z e d u s i n g a m u l t i v a r i a t e D i s c r i m i n a n t A n a l y s i s . T h i s i s a p a r t i c u l a r c a s e o f m u l t i p l e r e g r e s s i o n w h i c h a s s i g n s w e i g h t s t o i n d e p e n d e n t v a r i a b l e s i n o r d e r t h a t t h e w e i g h t e d sum o f s c o r e s w i l l p r o v i d e t h e b e s t p o s s i b l e d i f f e r e n t i a t i o n o r d i s c r i m i n a t i o n b e t w e e n two c r i t e r i o n g r o u p s . An a s s u m p t i o n made by t h i s a n a l y s i s i s t h a t t h e d a t a i s e x p r e s s e d i n s t a n d a r d s c o r e f o r m ( F e r g u s o n 1 9 8 1 , p . 4 7 3 ) . T h i s a s s u m p t i o n i s met s i n c e b o t h t h e WISC-R C o d i n g a n d B . C . Q . U . I . E . T . s c o r e s a r e r e c o r d e d i n t h i s f o r m . T h i s a n a l y s i s shows w h a t s u b t e s t o r c o m b i n a t i o n o f s u b t e s t s has t h e g r e a t e s t e f f e c t on c l a s s i f y i n g s o m e o n e a s a member o f e i t h e r t h e \" n o r m a l \" o r \" l e a r n i n g . 42 d i s a b l e d \" g r o u p . Summary F o u r g r o u p s o f s u b j e c t s , t w o c o n s i s t i n g o f s t u d e n t s d e f i n e d as n o r m a l a n d two d e f i n e d a s l e a r n i n g d i s a b l e d w e r e s e l e c t e d f r o m two s c h o o l d i s t r i c t s , C h i l l i w a c k and Kamloops. E a c h s t u d e n t was a d m i n i s t e r e d a WISC-R C o d i n g s u b t e s t and t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . , a c c o r d i n g t o t h e i r p u b l i s h e d s t a n d a r d i z e d p r o c e d u r e , on t h e same day. The m o r n i n g f o l l o w i n g t h i s a d m i n i s t r a t i o n e a c h s t u d e n t was r e t e s t e d w i t h t h e WISC-R C o d i n g s u b t e s t . D a t a f r o m t h e s e t e s t s were c o m p i l e d a n d a p p r o p r i a t e t - t e s t s ( d e p e n d a n t o r i n d e p e n d e n t ) w e r e p e r f o r m e d t o t e s t t h e f i r s t t h r e e h y p o t h e s e s , t o s e e w h e t h e r s i g n i f i c a n t t e s t - r e t e s t d i f f e r e n c e s o c c u r b etween t h e n o r m a l a n d l e a r n i n g d i s a b l e d g r o u p s . P e a r s o n p r o d u c t - m o m e n t c o r r e l a t i o n c o e f f i c i e n t s were c a l c u l a t e d b etween t h e WISC-R and B . C . Q . U . I . E . T . s u b t e s t s c o r e s t o s e e i f a n y s i g n i f i c a n t c o r r e l a t i o n s e x i s t e d among a n y o f t h e s e s u b t e s t s . F i n a l l y a m u l t i v a r i a t e d i s c r i m i n a n t a n a l y s i s . w a s p e r f o r m e d on t h e r e s u l t s f r o m t h e s u b t e s t s a d m i n i s t e r e d t o s e e w h i c h s u b t e s t o r c o m b i n a t i o n t h e r e o f h a d t h e g r e a t e s t e f f e c t o n c l a s s i f y i n g a s t u d e n t a s a member o f e i t h e r o f t h e two g r o u p s . The n e x t c h a p t e r w i l l p r e s e n t t h e r e s u l t s o f t h e s t u d y . I t w i l l a n a l y z e t h e d a t a and t a b l e s w i l l show, t h e s t a t i s t i c a l a n a l y s e s p e r f o r m e d . . 43 C H A P T E R I V R e s u l t s A n a l y s i s o f t h e d a t a T h i s c h a p t e r p r e s e n t s t h e d e s c r i p t i v e d a t a and t h e r e s u l t s f r o m s t a t i s t i c a l a n a l y s e s o f t h e d a t a . T h e s e d a t a a r e t h e n r e l a t e d t o t h e f i v e h y p o t h e s e s t e s t e d i n t h i s i n v e s t i g a t i o n . F o r t y s u b j e c t s f r o m g r a d e s two t o s i x w e r e a d m i n i s t e r e d t h e C o d i n g s u b t e s t o f t h e WISC-R i n a t e s t - r e t e s t f o r m a t w i t h t h e r e t e s t t a k i n g p l a c e t h e f o l l o w i n g d a y . A f t e r t h e a d m i n i s t r a t i o n o f t h e C o d i n g p r e t e s t , t h e s t u d e n t s who were c l a s s i f i e d as n o r m a l s were a d m i n i s t e r e d t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . T h e s u b j e c t s c l a s s i f i e d a s l e a r n i n g d i s a b l e d had a l l b een g i v e n t h e s u b t e s t s o f t h e B.C.Q.U.I.E.T. w i t h i n t h e l a s t 8 w e e k s . The s u b j e c t s w e r e d r a w n f r o m t w o e l e m e n t a r y s c h o o l s i n two s c h o o l d i s t r i c t s o f B r i t i s h C o l u m b i a , a n d t w o l e a r n i n g c e n t e r s f o r l e a r n i n g d i s a b l e d s t u d e n t s a s s o c i a t e d w i t h t h e two s c h o o l d i s t r i c t s . S u b j e c t s f r o m t h e t w o e l e m e n t a r y s c h o o l s were c l a s s i f i e d a s n o r m a l s i f i n s p e c t i o n o f t h e i r B . C . Q . U . I . E . T . s c o r e s r e v e a l e d ' t h a t a l l o f t h e f o u r s u b t e s t s c o r e s were a v e r a g e t o a b o v e , t h a t i s a n o r m a l - c u r v e e q u i v a l e n t (NCE) s c o r e o f 29.0 o r o v e r . Two s u b j e c t s f a i l e d t h i s c r i t e r i a a n d w e r e d i s c a r d e d f r o m f u r t h e r a n a l y s i s . The s u b j e c t s f r o m t h e l e a r n i n g c e n t e r s w e r e c l a s s i f i e d a s l e a r n i n g d i s a b l e d i f t h e i r WISC-R IQ s c o r e s w e r e i n a n o r m a l t o a b o v e r a n g e a n d i f t h e i r s c o r e s o n t h e B.C.Q.U.I.E.T. were below a v e r a g e f o r t h e i r a g e g r a d e l e v e l , t h a t i s a NCE s c o r e o f 28.9 o r l e s s ( W o r m e l i , 1 9 8 2 ) . T h i s c r i t e r i a i s s i m i l a r t o t h a t u s e d i n o t h e r s t u d i e s w h i c h . 44 l a b e l l e d s u b j e c t s a s l e a r n i n g d i s a b l e d i f t h e i r IQ was i n a n o r m a l t o a b o v e r a n g e and t h e y had been r e f e r r e d t o a l e a r n i n g o r r e s o u r c e c e n t e r ( H a l e , 1978; L y l e & Goyen, 1969; T a b a c h n i c k , 1979; Vance e t a l . , 1 9 8 0 ) . T h i s c l a s s i s f i c a t i o n r e s u l t e d i n f o u r g r o u p s b e i n g f o r m e d . T h e two n o r m a l g r o u p s f r o m t h e C h i l l i w a c k a n d Kamloops S c h o o l D i s t r i c t s had 10 and 11 s u b j e c t s r e s p e c t i v e l y , a n d t h e two l e a r n i n g d i s a b l e d g r o u p s f r o m t h e s e two a r e a s had 10 and 7 s u b j e c t s r e s p e c t i v e l y . P r i o r t o a n y s t a t i s t i c a l a n a l y s i s o f t h e f i v e m a i n h y p o t h e s e s , d a t a were a n a l y z e d t o see i f t h e f o u r g r o u p s c o u l d be p o o l e d i n t o two, one n o r m a l and one l e a r n i n g d i s a b l e d g r o u p . T h e g r e a t e r n u m b e r i n e a c h g r o u p b y p o o l i n g w o u l d p r o v i d e g r e a t e r p o w e r f o r a n y s t a t i s t i c a l a n a l y s i s . I n d e p e n d e n t t - t e s t s on a l l f o u r m e a s u r e s o f t h e B . C . Q . U . I . E . T . , c o m p a r i n g t h e C h i l l i w a c k a n d K a m l o o p s n o r m a l g r o u p s i n d i c a t e d n o s i g n i f i c a n t d i f f e r e n c e s b e t w e e n t h e g r o u p s o n a n y o f t h e m e a s u r e s . T h i s s u g g e s t e d t h a t b o t h t h e C h i l l i w a c k and Kamloops g r o u p s c o u l d be p o o l e d t o f o r m o n e g r o u p l a b e l l e d \" n o r m a l . \" A s i m i l a r a n a l y s i s o f t h e l e a r n i n g d i s a b l e d g r o u p s showed i t was a l s o p o s s i b l e t o p o o l t h e s u b j e c t s f r o m t h e K a m l o o p s a n d C h i l l i w a c k r e g i o n a l c e n t e r s i n t o a g r o u p l a b e l l e d \" l e a r n i n g d i s a b l e d . \" R e s u l t s o f t h e s e a n a l y s e s a r e f o u n d i n T a b l e s 1 and 2. T a b l e 1 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r f o u r B.C.Q.U.I.E.T. s u b t e s t s (Normal g r o u p s : C - C h i l l i w a c k ; K - K a m l o o p s ) . S u b t e s t G roup X s n t - V a l u e * S p e l l i n g CPS KPS 6 6.34 ' 5 7.98 ... 12.87 20. 78 10 11 1.10 Math CPS KPS 52.41 59.42 20.58 17. 21 10 11 -0.85 Word ID CPS KPS 51 .44 55 .7 4 8.83 17. 86 10 11 0.56 P a s s Comp. CPS KPS 52 .24 59.07 12.19 13. 20 10 11 -1.23 * V a l u e o f t f o r s i g n i f i c a n c e = 2.09 (\u00C2\u00A3 < .05) T a b l e 2 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r f o u r B.C.Q.U.I.E.T. s u b t e s t s ( L e a r n i n g d i s a b l e d g r o u p s : C - C h i l l i w a c k ; K - K a m l o o p s ) . S u b t e s t G roup X s n t - V a l u e CLC 3.65 2.57 10 S p e l l i n g 0. 60 KLC 1.91 0.95 7 CLC 3.70 3.40 10 Math 0 .55 KLC 3.11 3.76 7 CLC 7.71 2.05 10 Word ID -0.15 KLC 8 .60 2.28 7 CLC 9.36 5.54 10 P a s s Comp. 0. 83 KLC 5.44 2.34 7 * L e v e l o f t f o r s i g n i f i c a n c e = 2.13 (JD < .05) .46 The main h y p o t h e s e s were a n a l y z e d u s i n g t h e p o o l e d s c o r e s f o r t h e two g r o u p s . D e p e n d e n t t - t e s t s ( F e r g u s o n , 1981) were u s e d t o a n a l y z e t h e s i g n i f i c a n c e o f g a i n s on t h e C o d i n g s u b t e s t f o r t h e two g r o u p s . The d a t a f r o m t h e s e a n a l y s e s a r e p r e s e n t e d i n T a b l e s 3 and 4. An i n d e p e n d e n t t - t e s t ( F e r g u s o n , 1981) was u s e d t o t e s t t h e s i g n i f i c a n c e o f t h e d i f f e r e n c e between t h e two g r o u p s b a s e d o n t h e i r C o d i n g s c o r e s . T h i s s t a t i s t i c i s p r e s e n t e d i n T a b l e s 5 a n d 6. T a b l e 7 shows t h e c o r r e l a t i o n b e t w e e n t h e C o d i n g a n d B . C . Q . U . I . E . T . s u b t e s t s f o r t h e two g r o u p s . T a b l e 8 shows t h e c o r r e l a t i o n f o r t h e B . C . Q . U . I . E . T . a n d C o d i n g s u b t e s t s f o r t h e two g r o u p s combined. R e s u l t s o f a d i s c r i m i n a n t a n a l y s i s w e r e c o m p u t e d u s i n g t h e OWMAR ( UBC)_ computer p r o g r a m . They a r e p r e s e n t e d i n T a b l e 9 a n d A p p e n d i x A. The r e s u l t s o f t h e s e a n a l y s e s a r e i m p o r t a n t t o a d i s c u s s i o n o f t h e h y p o t h e s e s . H y p o t h e s i s One: T h e r e w i l l be no s t a t i s t i c a l l y s i g n i f i c a n t t e s t - r e t e s t mean s c o r e d i f f e r e n c e o n t h e C o d i n g s u b t e s t f o r \" n o r m a l \" s t u d e n t s a t t h e .05 c o n f i d e n c e l e v e l . T h i s h y p o t h e s i s was r e j e c t e d . A s T a b l e 3 i n d i c a t e s t h e r e was c l e a r l y a s i g n i f i c a n t t e s t - r e t e s t mean s c o r e d i f f e r e n c e f o r t h e n o r m a l g r o u p ( t = 6.48,p_ < . 0 5 ) . T h i s m e a n s t h a t f o r t h e n o r m a l g r o u p , s t u d e n t s s c o r e d s i g n i f i c a n t l y h i g h e r on t h e r e t e s t . I t a l s o i n d i c a t e s t h a t some m e a s u r a b l e l e a r n i n g t o o k p l a c e between t h e two t e s t s w h i c h may- be an i n d i c a t o r o f l e a r n i n g p o t e n t i a l i n t h i s g r o u p . T a b l e 3 M e a n s , s t a n d a r d d e v i a t i o n s a n d t - t e s t v a l u e f o r n o r m a l s u b j e c t s ( T e s t - r e t e s t : WISC-R C o d i n g S u b t e s t ) X s n t - V a l u e T e s t 1 0 . 5 7 2 . 6 0 21 - 6 . 48 R e t e s t 1 3 . 0 5 2 . 7 2 21 V a l u e o f t f o r s i g n i f i c a n c e = 2 . 0 9 (p_ < .05 ) .48 H y p o t h e s i s Two: T h e r e w i l l b e no s t a t i s t i c a l l y s i g n i f i c a n t t e s t - r e t e s t mean s c o r e d i f f e r e n c e o n t h e C o d i n g s u b t e s t f o r \" l e a r n i n g d i s a b l e d \" s t u d e n t s a t t h e .05 c o n f i d e n c e l e v e l . As T a b l e 4 i n d i c a t e s t h i s h y p o t h e s i s was s u p p o r t e d a t t h e .001 l e v e l b u t n o t a t t h e .05 l e v e l . T h i s r e s u l t c o n c u r s w i t h o t h e r s t u d i e s a t t h e .001 l e v e l ( S o l l y 1 9 7 7 , S m i t h 1 9 7 8 ) w h i c h s u p p o r t e d t h i s h y p o t h e s i s . T h i s f i n d i n g seems t o i n d i c a t e t h a t t h e s e s t u d e n t s have a l i m i t e d p o t e n t i a l t o l e a r n f r o m t h e f i r s t t e s t , p e r h a p s a l s o i n d i c a t i n g a m e a s u r e o f t h e i r l e a r n i n g p o t e n t i a l . T a b l e 4 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e s f o r l e a r n i n g d i s a b l e d s u b j e c t s ( T e s t - r e t e s t : WISC-R C o d i n g S u b t e s t ) X s n t - v a l u e t e s t 8.00 2.45 17 r e t e s t 9.18 3.05 17 -2.98 * V a l u e o f t f o r s i g n i f i c a n c e = 4.01 (p_ < .001) .50 H y p o t h e s i s T h r e e : T h e r e w i l l be no s t a t i s t i c a l l y s i g n i f i c a n t mean s c o r e d i f f e r e n c e between \" n o r m a l \" and \" l e a r n i n g d i s a b l e d \" s t u d e n t s o n t h e i n i t i a l a n d r e t e s t C o d i n g s c o r e a t t h e .05 c o n f i d e n c e l e v e l . T h i s h y p o t h e s i s was r e j e c t e d . As T a b l e 5 i n d i c a t e s t h e n o r m a l s u b j e c t s c l e a r l y s c o r e d s i g n i f i c a n t l y h i g h e r t h a n t h e l e a r n i n g d i s a b l e d g r o u p o n t h e i n i t i a l a d m i n i s t r a t i o n o f t h e C o d i n g s u b t e s t ( t = 3.11, p_ < . 0 5 ) . An a n a l y s i s o f t h e i r r e t e s t s c o r e s a s p r e s e n t e d i n T a b l e 6 c l e a r l y i n d i c a t e s t h a t a g a i n t h e n o r m a l s u b j e c t s s c o r e d s i g n i f i c a n t l y h i g h e r t h a n t h e l e a r n i n g d i s a b l e d s u b j e c t s ( t = 4.13,p_ < . 0 5 ) . R e s u l t s f r o m a n a l y z i n g t h e d a t a o f H y p o t h e s i s t h r e e seem t o i n d i c a t e t h a t t h e n o r m a l s u b j e c t s s c o r e d h i g h e r o n t h e C o d i n g s u b t e s t t h a n t h e l e a r n i n g d i s a b l e d s t u d e n t s . T h i s was t r u e n o t o n l y o f t h e i r s c o r e s on t h e i n i t i a l a d m i n i s t r a t i o n o f t h e t e s t b u t a l s o on t h e r e t e s t . F u r t h e r m o r e , t h e n o r m a l g r o u p seemed t o e x h i b i t a g r e a t e r g a i n b etween t h e i n i t i a l t e s t s c o r e (X = 1 0 . 5 7 ) a n d t h e r e t e s t s c o r e (X = 1 3 . 0 5 ) , a s compared t o t h e i n i t i a l t e s t (X = 8.00) and r e t e s t s c o r e s (X = 9.18) o f t h e l e a r n i n g d i s a b l e d g r o u p . T h i s f i n d i n g c o m p a r e s f a v o u r a b l y t o t h a t o f p r e v i o u s r e s e a r c h ( S o l l y , 1977) w h i c h f o u n d s i m i l a r r e s u l t s . T a b l e 5 Means, s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e b e tween n o r m a l and l e a r n i n g d i s a b l e d s u b j e c t s (WISC-R C o d i n g S u b t e s t ) G r o u p s X s n t - v a l u e s N o r m a l s 10.57 2.60 21 3.11 D i s a b l e d 8.00 2.45 17 * V a l u e o f t f o r s i g n i f i c a n c e = 2.04 (p_ < .05 T a b l e 6 Means s t a n d a r d d e v i a t i o n s and t - t e s t v a l u e b e t w e e n n o r m a l and l e a r n i n g d i s a b l e d s u b j e c t s ( R e t e s t : WISC-R C o d i n g S u b t e s t ) G r o u p s X s n t - v a l u e N o r m a l s 13.05 2.72 21 4 .13 D i s a b l e d 9.18 3.05 17 * V a l u e o f t f o r s i g n i f i c a n c e = 2.04 (p_ < .05) .52 H y p o t h e s i s F o u r : T h e r e w i l l b e no s t a t i s t i c a l l y s i g n i f i c a n t c o r r e l a t i o n between t h e C o d i n g s u b t e s t s c o r e s and e a c h o f t h e f o u r s u b t e s t s c o r e s o f t h e B.C.Q.U.I.E.T. f o r b o t h \" n o r m a l \" and \" l e a r n i n g d i s a b l e d \" s t u d e n t s , f i r s t s e p a r a t e l y a n d t h e n c o m b i n e d , a t t h e .05 c o n f i d e n c e l e v e l . T h i s H y p o t h e s i s was s u p p o r t e d . As T a b l e 7 i n d i c a t e s t h e r e c l e a r l y was no p o s i t i v e c o r r e l a t i o n b e t w e e n t h e i n i t i a l C o d i n g s c o r e a n d a n y o f t h e s u b t e s t s o f t h e B . C . Q . U . I . E . T . f o r e i t h e r n o r m a l o r l e a r n i n g d i s a b l e d s u b j e c t s . A n o t h e r f i n d i n g was t h a t t h e p o s t t e s t C o d i n g s c o r e d i d n o t c o r r e l a t e s i g n i f i c a n t l y w i t h t h e p r e t e s t C o d i n g s c o r e f o r t h e n o r m a l g r o u p , b u t c o r r e l a t e d s i g n i f i c a n t l y t o t h e p r e t e s t C o d i n g s c o r e f o r t h e l e a r n i n g d i s a b l e d g r o u p . F u r t h e r m o r e , f o r t h e n o r m a l g r o u p t h e p o s t t e s t C o d i n g s c o r e c o r r e l a t e d s i g n i f i c a n t l y w i t h a l l t h e s u b t e s t s o f t h e B . C . Q . U . I . E . T . C o n v e r s e l y , t h i s was n o t t r u e f o r t h e l e a r n i n g d i s a b l e d g r o u p . T h e i r p o s t t e s t s c o r e d i d n o t c o r r e l a t e s i g n i f i c a n t l y w i t h any o f t h e B.C.Q.U.I.E.T. s u b t e s t s . T a b l e 8 shows a c o r r e l a t i o n m a t r i x f o r t h e t o t a l c o m b i n e d sample p o p u l a t i o n . As t h i s a n a l y s i s u s e d a sample o f 38 i t c a n be c o n f i d e n t l y i n t e r p r e t e d ( F e r g u s o n , 1 9 8 1 ) . T h i s s u p p o r t s t h e p r e v i o u s a n a l y s i s i n t h a t i t shows no s i g n i f i c a n t c o r r e l a t i o n s b e t w e e n t h e C o d i n g p r e t e s t a n d a n y o f t h e o t h e r s u b t e s t s . A g a i n however, t h e C o d i n g p o s t t e s t seems t o be s i g n i f i c a n t l y c o r r e l a t e d w i t h S p e l l i n g , Word I d e n t i f i c a t i o n , . a n d t h e P a s s a g e C o m p r e h e n s i o n s u b t e s t s o f t h e B.C.Q.U.I.E.T. . 53 A n o t h e r f i n d i n g was t h a t i n a l l o f t h e c o r r e l a t i o n a n a l y s i s t h e M a t h s u b t e s t o f t h e B . C . Q . U . I . E . T . d i d n o t c o r r e l a t e s i g n i f i c a n t l y w i t h e i t h e r t h e p r e o r p o s t t e s t C o d i n g s c o r e s . An e x c e p t i o n was i n t h e c a s e o f C o d i n g p o s t t e s t i n t h e n o r m a l g r o u p w h e r e i t was s t a t i s t i c a l l y b u t n o t p r a c t i c a l l y s i g n i f i c a n t . T a b l e 7 P e a r s o n r c o r r e l a t i o n c o e f f i c i e n t s between WISC-R C o d i n g and B.C.Q.U.I.E.T. s u b t e s t s c o r e s ( N o r m a l s - u p p e r h a l f , L e a r n i n g D i s a b l e d - l o w e r ) Coding S p e l l i n g Math Word ID Pass Comp Coding2 Normals Coding \u00E2\u0080\u0094 0. .08 0. .06 -0. .05 0. .07 -0. .03 S p e l l i n g -0. .15 - 0. .71* 0. .86* 0. .77* 0. .60* Math -0. .10 -0. .14 - 0. .85* 0. .72* 0. .49* Word ID -0. .37 0. .01 0. .75* - 0. .83* 0, .69* Pass Comp -0. .05 0. .18 -0. .11 -0. .01 - 0. .71* Coding2 0. .93* -0, .04 -0. .04 -0. .27 -0. .23 -Learning Disabled <. 05 T a b l e 8 Pearson r c o r r e l a t i o n c o e f f i c i e n t s between WISC-R Coding and B.C.Q.U.I.E.T. subtest scores (Normal and Learning Disabled scores pooled) S p e l l i n g Math Word ID Pass Ccmp Coding2 Coding 0.033 -0.065 -0. .180 0. .063 0. .329* S p e l l i n g 0.253 0. .637* 0. .624* 0. .413* Math - - 0. .713* 0. .180 0. .123 Word ID - - - 0. .506* 0. .257 Pass Comp - - - - 0. .315 p_ < .05 \u00E2\u0080\u00A2 55 H y p o t h e s i s F i v e : T h e r e w i l l be no s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e \" n o r m a l \" a n d \" l e a r n i n g d i s a b l e d \" s t u d e n t s o n t h e c o m b i n e d m e a n s c o r e o f t h e WISC-R C o d i n g s u b t e s t a n d t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . T h i s h y p o t h e s i s was r e j e c t e d a f t e r b e i n g t e s t e d by a d i s c r i m i n a n t - a n a l y s i s u s i n g t h e OWMAR (UBC) c o m p u t e r p r o g r a m . The r e s u l t s o f a B a r t l e t t - B o x H o m o g e n e i t y o f D i s p e r s i o n T e s t , a m u l t i v a r i a t e a n a l y s i s o f v a r i a n c e , shows t h a t t h e r e i s a c l e a r l y s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e n o r m a l and l e a r n i n g d i s a b l e d g r o u p s as a r e s u l t o f t h e i r c ombined s c o r e s on a l l s i x o f t h e s u b t e s t s (F = 3.25, p_ < .0001). T a b l e 9 p r e s e n t s t h e w e i g h t s t o b e a s s i g n e d t o t h e i n d i v i d u a l s u b t e s t s c o r e s t o d e t e r m i n e w h e t h e r o r n o t t h e i n d i v i d u a l b e l o n g s i n t h e n o r m a l o r l e a r n i n g d i s a b l e d g r o u p . A l i s t o f e a c h i n d i v i d u a l ' s combined, w e i g h t e d s c o r e i s p r e s e n t e d i n A p p e n d i x A. T h i s s h o w s t h a t t h e d i s c r i m i n a n t a n a l y s i s a c c u r a t e l y p l a c e d \"each i n d i v i d u a l i n t h e a p p r o p r i a t e g r o u p ( i . e . a l l t h e s u b j e c t s i n t h e n o r m a l g r o u p s t a y e d i n t h a t g r o u p , l i k e w i s e f o r t h e l e a r n i n g d i s a b l e d ) . F u r t h e r e x a m i n a t i o n o f T a b l e 9 shows t h a t t h e v a r i a b l e t h a t was t h e g r e a t e s t c o n t r i b u t o r t o t h e d i f f e r e n c e was Word I d e n t i f i c a t i o n . T h i s was f o l l o w e d b y t h e M a t h , S p e l l i n g , C o d i n g , C o d i n g 2 and P a s s a g e C o m p r e h e n s i o n s u b t e s t s . T h i s means t h a t a s u b j e c t ' s c o m b i n e d WISC-R C o d i n g and B.C.Q.U.I.E.T. s c o r e , w e i g h t e d by t h e d i s c r i m i n a n t a n a l y s i s , c o u l d b e u s e d t o p l a c e a s u b j e c t i n e i t h e r t h e n o r m a l o r l e a r n i n g d i s a b l e d g r o u p . . 56 T a b l e 9 D i s c r i m i n a n t A n a l y s i s Subtest Normalized Raw Score Weights f o r C l a s s i f i c a t i o n Normalized Standard Score Weights f o r C l a s s i f i c a t i o n Coding 0.179967 0.206385 S p e l l i n g 0.495041 0.280641 Math -0.243312 -0.466642 Word ID 0.757098 0.777135 ^ Pass. Comp. -0.237169 -0.124579 Coding2 -0.184117 -0.203547 Eigenvalue = 11.758572 * I f combined weighted score exceeded Eigenvalue, subject was c l a s s i f i e d as normal, otherwise as learning disabled. .57 Summary In t h i s c h a p t e r d a t a was c o l l e c t e d i n t h e f o r m o f WISC-R C o d i n g s u b t e s t p r e and p o s t t e s t s c o r e s a l o n g w i t h s c o r e s f r o m a d m i n i s t e r i n g t h e f o u r s u b t e s t s o f t h e B.C.Q.U.I.E.T. t o 17 s u b j e c t s c l a s s i f i e d a s \" l e a r n i n g d i s a b l e d \" a n d 21 s u b j e c t s i c l a s s i f i e d a s \" n o r m a l . \" S i n c e t h e s u b j e c t s c a m e f r o m t w o s e p a r a t e s c h o o l s i n two s e p a r a t e s c h o o l d i s t r i c t s and l e a r n i n g c e n t e r s , s u b j e c t s ' s c o r e s w e r e f i r s t a n a l y z e d t o see i f t h e y c o u l d be p o o l e d so t h a t f u r t h e r a n a l y s e s c o u l d d e r i v e g r e a t e r w e i g h t f r o m t h e l a r g e r number o f p o o l e d s c o r e s . S t a t i s t i c a l a n a l y s e s u s i n g t - t e s t s f o u n d t h a t t h e r e was a d i f f e r e n c e b e t w e e n t h e p r e a n d p o s t t e s t C o d i n g s c o r e s f o r t h e n o r m a l g r o u p , a n d between t h e n o r m a l and l e a r n i n g d i s a b l e d g r o u p . No s i g n i f i c a n t p r e and p o s t t e s t d i f f e r e n c e s on t h e C o d i n g t e s t by l e a r n i n g d i s a b l e d s u b j e c t s w e r e f o u n d t o e x i s t a t t h e .001 l e v e l o f c o n f i d e n c e . A P e a r s o n r c o r r e l a t i o n c o e f f i c i e n t a n a l y s i s f o u n d s i g n i f i c a n t b e t w e e n a l l f o u r o f t h e B . C . Q . U . I . E . T . s u b t e s t s a n d t h e p o s t t e s t C o d i n g s c o r e f o r n o r m a l s u b j e c t s . F o r t h e l e a r n i n g d i s a b l e d s u b j e c t s C o d i n g c o r r e l a t e d s i g n i f i c a n t l y w i t h t h e C o d i n g r e t e s t . A m u l t i v a r i a t e d i s c r i m i n a n t a n a l y s i s s u p p o r t e d t h e a n a l y s i s u s i n g t - t e s t s and f o u n d t h a t s u b j e c t s c o u l d be c l a s s i f i e d a s n o r m a l o r l e a r n i n g d i s a b l e d by u s i n g a c o m b i n a t i o n o f t h e i r C o d i n g and B.C.Q.U.I.E.T. s u b t e s t s c o r e s . T h e n e x t c h a p t e r w i l l d i s c u s s t h e i m p l i c a t i o n s o f t h e s e a n a l y s e s . I t w i l l a l s o d i s c u s s t h e l i m i t a t i o n s o f t h e s t u d y and g i v e d i r e c t i o n s f o r f u t u r e r e s e a r c h . . 58 CHAPTER V D i s c u s s i o n and I m p l i c a t i o n s T h e p u r p o s e o f t h i s s e c t i o n i s t o i n t e r p r e t and d i s c u s s t h e r e s u l t s o f t h e d a t a p r e s e n t e d i n C h a p t e r IV a s w e l l a s t o i n t e g r a t e t h e s e r e s u l t s w i t h p r e v i o u s r e s e a r c h . T h e i m p l i c a t i o n s o f t h i s s t u d y w i l l b e p r e s e n t e d a s w e l l a s i t s l i m i t a t i o n s . T h e s e i m p l i c a t i o n s w i l l f o c u s on t h r e e m a i n a r e a s w h i c h were i n v e s t i g a t e d i n t h e s t u d y . T h e s e a r e : - I m p l i c a t i o n s o f t e s t - r e t e s t a n d p r a c t i c e e f f e c t on t h e WISC-R C o d i n g s u b t e s t . -The r e s u l t s o f c o r r e l a t i o n s b e t w e e n t h e WISC-R C o d i n g s u b t e s t and t h e f o u r s u b t e s t s o f t h e B.C.Q.U.I.E.T. - R e s u l t s o f t h e m u l t i v a r i a t e d i s c r i m i n a n t a n a l y s i s . F i n a l l y a v i e w t o w a r d p o s s i b l e d i r e c t i o n s f u t u r e s t u d i e s c o u l d t a k e w i l l be d e s c r i b e d . P r a c t i c e e f f e c t on WISC-R C o d i n g s u b t e s t Some r e s e a r c h e r s , n o t a b l y B u d o f f ( 1 9 7 2 ) , a n d F e u e r s t e i n (1979) have r e a s o n e d t h a t a t e s t - r e t e s t p r o c e d u r e c o u l d measure l e a r n i n g p o t e n t i a l . T h e g r e a t e r t h e p r a c t i c e e f f e c t , d e t e r m i n e d b y t h e t e s t - r e t e s t p r o c e d u r e , t h e more l e a r n i n g p o t e n t i a l t h e s u b j e c t h a s . P r e v i o u s t e s t - r e t e s t s t u d i e s on t h e WISC-R ( M a t a r r a z z o e t a l . , 19 7 3; Q u e r e s h i , 1 9 6 8 ; Tuma & Applebaum, 1 9 8 0 ) , had r e p o r t e d s i g n i f i c a n t g a i n s i n t h e C o d i n g s u b t e s t by n o r m a l p o p u l a t i o n s . T hese s t u d i e s l e n d s u p p o r t t o t h e i d e a t h a t t h e r e i s a s i g n i f i c a n t p r a c t i c e e f f e c t on t h e r e t e s t o f t h e WISC-R C o d i n g s u b t e s t f o r n o r m a l s u b j e c t s . T h i s a l s o s u g g e s t s t h a t i f t h e p r a c t i c e e f f e c t i s v e r y s m a l l o r \u00E2\u0080\u00A2 5 9 n o n - e x i s t e n t , a s h a s b e e n f o u n d i n some s t u d i e s w i t h l e a r n i n g d i s a b l e d s u b j e c t s (Lombard & R e i d e l , 1978; S m i t h , 1978; S o l l y , 1 9 7 7 ) , i t may be p o s s i b l e t o u s e t h e e f f e c t t o e v a l u a t e w h e t h e r a s t u d e n t i s n o r m a l o r l e a r n i n g d i s a b l e d . T h i s may b e a p p r o p r i a t e i f t h e r e i s any q u e s t i o n i n d e t e r m i n i n g w h e t h e r a s t u d e n t i s t r u l y l e a r n i n g d i s a b l e d o r h a s b e e n p r e v i o u s l y m i s d i a g n o s e d . E x c e p t p e r h a p s f o r S o l l y ' s ( 1 9 7 7 ) s t u d y , w h i c h c o m p a r e d g i f t e d t o r e t a r d e d s t u d e n t s no r e s e a r c h h as b e e n r e p o r t e d i n w h i c h t e s t - r e t e s t d a t a on t h e WISC-R C o d i n g s u b t e s t f o r n o r m a l s t u d e n t s has been compared t o s t u d e n t s w i t h l e a r n i n g p r o b l e m s . T h i s s t u d y h a s a t t e m p t e d t o c o m p a r e t e s t - r e t e s t d a t a f r o m n o r m a l s t u d e n t s t o t h a t o b t a i n e d f r o m l e a r n i n g d i s a b l e d s t u d e n t s , m a t c h e d i n t e r m s o f a g e , S E S , a n d l o c a l i t y , t h u s p r o v i d i n g a b e t t e r d e s i g n f o r d e t e r m i n i n g i f t h e two g r o u p s c o u l d b e d i s t i n q u i s h e d b y t h e i r p e r f o r m a n c e o n t h e WISC-R C o d i n g s u b t e s t . In t h i s s t u d y two s a m p l e s o f s t u d e n t s f r o m p u b l i c s c h o o l s i n B r i t i s h C o l u m b i a w e r e compared by t h e i r s c o r e s on t h e f o u r s u b t e s t s o f t h e B . C . Q . U . I . E . T . ( W o r m e l i , 1982) a n d a p r e and p o s t t e s t o f t h e WISC-R C o d i n g s u b t e s t ( W e c h s l e r , 1 9 7 4 ) . One g r o u p was composed o f \" n o r m a l \" s t u d e n t s f r o m r e g u l a r c l a s s r o o m s a n d t h e o t h e r o f \" l e a r n i n g d i s a b l e d \" s t u d e n t s f r o m l e a r n i n g c e n t e r s . a s s o c i a t e d w i t h t h e d i s t r i c t s f r o m w h i c h t h e \" n o r m a l \" s a mple was drawn. The n o r m a l g r o u p c o n s i s t e d o f 21 s u b j e c t s , t h e l e a r n i n g d i s a b l e d g r o u p o f 17. The c r i t e r i a f o r s e l e c t i n g t h e l e a r n i n g d i s a b l e d s t u d e n t s was s i m i l a r t o t h a t o f o t h e r s t u d i e s on t h e W e c h s l e r I n t e l l i g e n c e S c a l e s , i n t h a t t h e y w e r e .60 r e f e r r e d t o a l e a r n i n g c e n t e r b e c a u s e o f l e a r n i n g d i f f i c u l t i e s i n s c h o o l , b u t had a v e r a g e t o above IQ s c o r e s ( H a l e , 1978; L y l e & Goyen, 1969; T a b a c h n i c k , 1979; Vance e t a l . 1 9 8 0 ) . I t was b e l i e v e d t h a t o v e r a s h o r t r e t e s t p e r i o d t h e r e w o u l d b e a s i g n i f i c a n t g a i n f o r t h e n o r m a l s u b j e c t s o n t h e WISC-R C o d i n g s u b t e s t . T h i s h y p o t h e s i s was s u p p o r t e d by t h e d a t a . I t a d d s f u r t h e r s u p p o r t t o s t u d i e s w h i c h f o u n d s i g n i f i c a n t g a i n s i n t h e C o d i n g s u b t e s t b y n o r m a l p o p u l a t i o n s i n t e s t - r e t e s t s t u d i e s on t h e WISC-R ( M a t a r r a z z o e t a l . , 1973; Q u e r e s h i , 1968; Tuma & Appelbaum, 1 9 8 0 ) . I t w as b e l i e v e d t h a t t h i s s t u d y w o u l d s u p p o r t t h e l i t e r a t u r e i n f i n d i n g no s i g n i f i c a n t g a i n i n t h e r e t e s t s c o r e s o f t h e WISC-R C o d i n g s u b t e s t o f l e a r n i n g d i s a b l e d s u b j e c t s , t h u s i m p l y i n g t h a t t h e l e a r n i n g p o t e n t i a l o f t h i s g r o u p was l e s s t h a n t h a t o f n o r m a l s u b j e c t s . I t w a s . f o u n d i n t h i s s t u d y t h a t t h e r e was no s i g n i f i c a n t g a i n by t h e l e a r n i n g d i s a b l e d s u b j e c t s a t t h e .001 l e v e l o f p r o b a b i l i t y . The r e s u l t a t t h e .001 l e v e l s u p p o r t e d o t h e r r e s e a r c h w h i c h f o u n d s i m i l a r r e s u l t s w i t h o t h e r l e a r n i n g d i s a b l e d s u b j e c t s (Lombard & R e i d e l , 1978 ; C a t r o n & C a t r o n , 1 9 7 7 ) . T h i s r e s u l t a l s o s u p p o r t s t h e i d e a t h a t t h e l e a r n i n g d i s a b l e d s u b j e c t s h a v e a l o w e r mean g a i n on t h e r e t e s t o f t h e t h e WISC-R C o d i n g s u b t e s t t h a n n o r m a l s u b j e c t s . S u p p o r t f o r t h i s i s g i v e n by t h e r e j e c t i o n o f h y p o t h e s i s t h r e e , t h a t t h e r e i s no d i f f e r e n c e b e t w e e n t h e n o r m a l a n d l e a r n i n g d i s a b l e d g r o u p s as a r e s u l t o f t h e i r C o d i n g s c o r e s . An a n a l y s i s o f t h e d a t a s h o w s t h e r e a r e s i g n i f i c a n t d i f f e r e n c e s between t h e two g r o u p s b o t h o n t h e i r p r e a n d p o s t t e s t s c o r e s o n t h e WISC-R . 61 C o d i n g s u b t e s t . WISC-R C o d i n g and B.C.Q.U.I.E.T. c o r r e l a t i o n s I n p r e v i o u s f a c t o r a n a l y s i s t h e WISC-R C o d i n g s u b t e s t was p u t i n t o a c a t e g o r y w i t h t h e WISC-R A r i t h m e t i c s u b t e s t b e c a u s e t h e C o d i n g s u b t e s t c o r r e l a t e d m o s t h i g h l y w i t h t h e A r i t h m e t i c s u b t e s t (Kaufman, 1 9 7 5 ) . However, i n t h e c a s e o f b o t h n o r m a l a n d l e a r n i n g d i s a b l e d g r o u p s i n t h i s s t u d y , n e i t h e r t h e p r e o r p o s t t e s t C o d i n g s c o r e s c o r r e l a t e d s i g n i f i c a n t l y w i t h t h e B.C.Q.U.I.E.T. A r i t h m e t i c s u b t e s t . A c o n c l u s i o n w h i c h may be d r a w n f r o m t h i s i s t h a t t h e WISC-R A r i t h m e t i c s u b t e s t , b e i n g v e r b a l l y b a s e d , m e a s u r e s s o m e t h i n g d i f f e r e n t t h a n t h e A r i t h m e t i c s u b t e s t o f t h e B.C.Q.U.I.E.T., w h i c h i s p e r f o r m a n c e b a s e d , e v e n t h o u g h s u p e r f i c i a l l y t h e two t e s t s seem t o be m e a s u r i n g t h e same t h i n g . A n o t h e r f i n d i n g was t h a t t h e C o d i n g p r e t e s t , w h i c h i s t h e s u b t e s t s c o r e u s e d i n t h e WISC-R a s s e s s m e n t p r o c e s s , d i d n o t c o r r e l a t e s i g n i f i c a n t l y w i t h any o f t h e B.C.Q.U.I.E.T. s u b t e s t s c o r e s f o r e i t h e r t h e n o r m a l o r l e a r n i n g d i s a b l e d g r o u p . On t h e o t h e r h a n d , t h e C o d i n g p o s t t e s t s c o r e s c o r r e l a t e d s i g n i f i c a n t l y w i t h a l l o f t h e B.C.Q.U.I.E.T. s u b t e s t s f o r t h e n o r m a l g r o u p . S i n c e i n . most o t h e r r e s e a r c h (Kaufman, 1979 ) t h e WISC-R C o d i n g s u b t e s t h a s s e l d o m c o r r e l a t e d v e r y h i g h l y w i t h any o t h e r s u b t e s t o f t h e WISC-R, o r any a c h i e v e m e n t t e s t s c o r e f o r t h a t m a t t e r , d o e s t h i s i m p l y t h a t p e r h a p s t h e WISC-R C o d i n g s u b t e s t s h o u l d be a d m i n i s t e r e d a s e c o n d t i m e s h o r t l y a f t e r t h e f i r s t f o r t h i s s u b t e s t t o have a s s e s s m e n t v a l u e ? P e r h a p s t h i s i s why most f a c t o r a n a l y s e s d o n e o n t h e WISC-R C o d i n g s u b t e s t . 62 p o i n t o u t t h a t C o d i n g m e a s u r e s s o m e t h i n g u n i q u e , n o t r e l a t e d t o a n y o f t h e o t h e r W I S C - R s u b t e s t s . I f C o d i n g w e r e r e a d m i n i s t e r e d s h o r t l y a f t e r t h e f i r s t t e s t s e s s i o n and t h i s s c o r e i n c l u d e d i n t h e f a c t o r a n a l y s i s w o u l d C o d i n g t h e n show a c l o s e r r e l a t i o n s h i p t o o t h e r s u b t e s t s o f t h e WISC-R? I t was a l s o i n t e r e s t i n g t o n o t e t h e a b s e n c e o f a n y r e l a t i o n s h i p between t h e C o d i n g p r e t e s t and p o s t t e s t s c o r e s f o r n o r m a l c h i l d r e n ( r = - 0 . 0 3 ) . T h i s may s i g n i f y t h a t n o r m a l c h i l d r e n have d i f f e r e n t l e v e l s o f l e a r n i n g p o t e n t i a l , t h a t some l e a r n more f r o m t h e p r e t e s t t h a n o t h e r s . However t h i s f i n d i n g was n o t s u p p o r t e d by p r e v i o u s r e s e a r c h . G e n e r a l l y C o d i n g h a s b e e n f o u n d t o b e among t h e most s t a b l e o f t h e WISC-R s u b t e s t s w i t h h i g h t e s t - r e t e s t r e l i a b i l i t y ( r = .67 t o .88) i n m o s t s t u d i e s . As m o s t p r e v i o u s s t u d i e s h a v e s h o w n t h e C o d i n g s u b t e s t r e t e s t r e l i a b i l i t y c o e f f i c i e n t s t o become more s t a b l e o v e r t i m e , and s i n c e p r e v i o u s s t u d i e s were o f t e n c o n d u c t e d o v e r l o n g e r r e t e s t p e r i o d s o f f r o m one week t o t h r e e y e a r s , t h e ' v e r y s h o r t (24 h o u r s ) r e t e s t p e r i o d o f t h i s s t u d y may h a v e c o n t r i b u t e d s i g n i f i c a n t l y t o t h e l o w t e s t - r e t e s t c o r r e l a t i o n c o e f f i c i e n t . F o r l e a r n i n g d i s a b l e d s u b j e c t s however, t h e r e was a v e r y h i g h t e s t - r e t e s t c o r r e l a t i o n c o e f f i c i e n t ( r = . 9 3 ) . T h i s shows t h a t f o r t h i s g r o u p t h e p r a c t i c e e f f e c t was v e r y s t a b l e and p e r h a p s i n d i c a t e s t h a t t h e m e m b e r s o f t h i s g r o u p h a v e r e l a t i v e l y e q u a l l e v e l s o f l e a r n i n g p o t e n t i a l . T h i s f i n d i n g was i n a c c o r d a n c e w i t h m u c h o f t h e p r e v i o u s l i t e r a t u r e o n t e s t - r e t e s t r e l i a b i l i t y o f t h e WISC-R w h i c h shows C o d i n g t o be a r e l a t i v e l y s t a b l e s u b t e s t . One i m p l i c a t i o n o f t h e f i n d i n g s .63 i n t h i s s t u d y may b e t h a t f o r l e a r n i n g d i s a b l e d c h i l d r e n t e s t - r e t e s t r e l i a b i l i t y o f t h e WISC-R C o d i n g s u b t e s t i s s t a b l e o v e r b o t h l o n g t e r m and v e r y s h o r t t i m e i n t e r v a l s . T h e s e f i n d i n g s seem t o s u p p o r t t h e i d e a t h a t t h e WISC-R C o d i n g s u b t e s t may m e a s u r e l e a r n i n g p o t e n t i a l . F i r s t t h e t e s t - r e t e s t c o r r e l a t i o n o f t h e n o r m a l g r o u p o n t h e C o d i n g s u b t e s t i s m i n i m a l ( r = -0.03) i n d i c a t i n g d i f f e r i n g l e v e l s o f l e a r n i n g ( f r o m t h e p r e t e s t ) a b i l i t y . S e c o n d t h e l e a r n i n g d i s a b l e d g r o u p had a h i g h ( r = .93) t e s t - r e t e s t c o r r e l a t i o n on t h e C o d i n g s u b t e s t i n d i c a t i n g a s i m i l a r a b i l i t y o f t h e members o f t h i s g r o u p t o l e a r n f r o m t h e p r e t e s t . T h i r d , t - t e s t s on t h e t e s t - r e t e s t s c o r e s o f t h e C o d i n g s u b t e s t show s i g n i f i c a n t d i f f e r e n c e s f o r t h e n o r m a l g r o u p , i n d i c a t i n g t h e p o s t t e s t s c o r e was s i g n i f i c a n t l y h i g h e r t h a n t h e p r e t e s t s c o r e . F i n a l l y , t h e n o r m a l g r o u p s c o r e d s i g n i f i c a n t l y h i g h e r on b o t h t h e p r e and p o s t t e s t C o d i n g s u b t e s t t h a n t h e l e a r n i n g d i s a b l e d g r o u p . M u l t i v a r i a t e d i s c r i m i n a n t a n a l y s i s The r e s u l t s o f t h e d i s c r i m i n a n t a n a l y s i s show t h a t t h e r e i s a s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e n o r m a l a n d l e a r n i n g d i s a b l e d g r o u p s as a r e s u l t o f t h e i r c ombined s c o r e s on a l l s i x m e a s u r e s ( A p p e n d i x A ) . The c l e a r d i s t i n c t i o n between t h e two g r o u p s t h a t was made by t h e d i s c r i m i n a n t a n a l y s i s may make t h i s a n a l y s i s , u s i n g t h e s e s u b t e s t s , a m o re e f f i c i e n t m e t h o d o f i d e n t i f y i n g l e a r n i n g d i s a b l e d s t u d e n t s i n B r i t i s h C o l u m b i a . T h e s h o r t a d m i n i s t r a t i o n t i m e o f t h e B.C.Q.U.I.E.T. and WISC-R C o d i n g s u b t e s t s compares f a v o r a b l y t o t h a t o f c u r r e n t s c r e e n i n g methods w h i c h have a much l o n g e r a d m i n i s t r a t i o n t i m e . . 64 I n t h i s a n a l y s i s t h e W o r d I d e n t i f i c a t i o n , M a t h a n d S p e l l i n g s u b t e s t s o f t h e B . C . Q . U . I . E . T . w e r e g r e a t e r c o n t r i b u t o r s t o t h e d i f f e r e n c e t h a n e i t h e r t h e p r e o r p o s t t e s t C o d i n g s c o r e s . T h i s seems t o i m p l y t h a t C o d i n g i s an i n f e r i o r d i s c r i m i n a t o r . T h e r e a s o n f o r Word I d e n t i f i c a t i o n , M a t h a n d S p e l l i n g s u b t e s t s p r o v i d i n g g r e a t e r w e i g h t t o t h e d i s c r i m i n a n t a n a l y s i s c o u l d b e t h e f a c t t h a t t h e l e a r n i n g d i s a b l e d g r o u p d i d s o p o o r l y o n t h e s e m e a s u r e s , o f t e n s c o r i n g o n l y i n t h e f i r s t p e r c e n t i l e . F u r t h e r m o r e , t h e i r a b i l i t y on t h e s e m e asures was d i r e c t l y i n f l u e n c e d by what t h e y had l e a r n e d p r e v i o u s l y . B e i n g l e a r n i n g d i s a b l e d , t h e y w o u l d h a v e h a d d i f f i c u l t y l e a r n i n g a c a d e m i c m a t e r i a l , t h u s s c o r i n g p o o r l y o n t e s t s t h a t m e a s u r e t h e i r a c a d e m i c a c h i e v e m e n t . C o d i n g on t h e o t h e r hand i s n o t i n f l u e n c e d by p r e v i o u s a c a d e m i c l e a r n i n g and so s c o r e s on t h i s t e s t s h o u l d n o t be a s d i f f e r e n t b e t w e e n n o r m a l a n d l e a r n i n g d i s a b l e d s t u d e n t s a s t h e i r s c o r e s o n an a c h i e v e m e n t measure. I n o t h e r words t h e WISC-R C o d i n g s u b t e s t i s a d i f f e r e n t t y p e o f measure t h a n t h e B.C.Q.U.I.E.T. T h a t t h e two g r o u p s m i g h t a l s o h a v e b e e n s e p a r a t e d b y u s i n g o n l y t h e i r C o d i n g s c o r e s i s s u p p o r t e d by t h e f a c t t h a t t - t e s t s d i f f e r e n t i a t e d b e t w e e n t h e n o r m a l and l e a r n i n g d i s a b l e d g r o u p s by r e a s o n o f b o t h t h e i r p r e and p o s t t e s t C o d i n g s c o r e s . L i m i t a t i o n s o f t h e s t u d y T h i s s t u d y was i n t e n d e d t o r e s e a r c h t h e i d e a t h a t t h e C o d i n g s u b t e s t o f t h e WISC-R c o u l d be a p o s s i b l e m e a s u r e o f l e a r n i n g p o t e n t i a l and t o p r o v i d e i n s i g h t s i n t o w h a t a r e a s o f . 65 academic l e a r n i n g Coding might be a s s o c i a t e d w i t h . I t was not intended t o be a d e f i n i t i v e study on the WISC-R Coding subtest. Furthermore as the sample was r e l a t i v e l y s m a l l (38 subjects) some of t h e s t a t i s t i c a l a n a l y s i s must be a c c e p t e d w i t h r e s e r v a t i o n , e s p e c i a l l y the c o r r e l a t i o n s between the WISC-R C o d i n g s u b t e s t and the B.C.Q.U.I.E.T. s u b t e s t s . Both the normal and l e a r n i n g d i s a b l e d 'groups contained- l e s s than 30 s u b j e c t s which i s the l e a s t number r e q u i r e d for- a c c e p t a b l e c o r r e l a t i o n r e l i a b i l i t y (Ferguson, 1981). F i n a l l y the time i n t e r v a l between the t e s t and the r e t e s t of the Coding subtest was very short which some researchers c l a i m has a great deal of i n f l u e n c e on the p r a c t i c e e f f e c t (Matarrazzo et a l , 1973). D i r e c t i o n s f o r f u t u r e research Future research i n t h i s area s h o u l d be done w i t h l a r g e r samples. Furthermore the time i n t e r v a l between r e t e s t i n g needs to be r e s e a r c h e d . I t would a l s o be i n t e r e s t i n g to add a t h i r d group comprised of \" g i f t e d \" o r \" b r i g h t \" s u b j e c t s to a s i m i l a r study to see i f there would be any d i f f e r e n c e between them and the \"normal\" s u b j e c t s as a r e s u l t of t h e i r Coding scores. I t may a l s o be p e r t i n e n t to i n v e s t i g a t e the s i z e of the gain upon r e a d m i n i s t r a t i o n of the WISC-R Coding s u b t e s t . S i n c e t h e s t a b i l i t y o f t h e C o d i n g s u b t e s t has by now been w e l l e s t a b l i s h e d the amount of e r r o r i n the g a i n s c o r e may not be too s i g n i f i c a n t . T h i s may a l l o w us t o use t h e g a i n as an i n d i c a t i o n of a subject's l e a r n i n g p o t e n t i a l . F i n a l l y the t e c h n i q u e of u s i n g a d i s c r i m i n a n t a n a l y s i s w i t h the s u b t e s t s used i n t h i s study s h o u l d be r e p l i c a t e d to . 66 e s t a b l i s h t h a t t h e r e s u l t s o b t a i n e d i n t h i s s tudy were n o t due t o c h a n c e . I f t h e r e s u l t s o b t a i n e d i n t h i s s t u d y a r e u p h e l d t h i s t e c h n i q u e may p r o v e a b e t t e r , more e f f i c i e n t , and l e s s t i m e consuming way o f s c r e e n i n g l e a r n i n g d i s a b l e d s t u d e n t s . .67 BIBLIOGRAPHY B a b a d , E . Y . , & B u d o f f , M. S e n s i t i v i t y a n d v a l i d i t y o f a l e a r n i n g p o t e n t i a l p r o c e d u r e . J o u r n a l o f E d u c a t i o n a l P s y c h o l o g y , 1974 , .66_r 439-447. B a n n a t y n e , A. D i a g n o s i n g l e a r n i n g d i s a b i l i t i e s a n d w r i t i n g r e m e d i a l p r e s c r i p t i o n s . J o u r n a l o f L e a r n i n g D i s a b i l i t i e s , 1968, 1, 4, 28-35. B a u m e i s t e r , A.A., & B a r t l e t t C . J . A c o m p a r i s o n o f t h e f a c t o r s t r u c t u r e o f n o r m a l s and r e t a r d a t e s o n t h e WISC. A m e r i c a n J o u r n a l o f M e n t a l D e f i c i e n c i e s , 1962 , 66^, 641-646. B o r t n e r , M. , & B i r c h , H.G. P a t t e r n s o f i n t e l l e c t u a l a b i l i t y i n e m o t i o n a l l y d i s t u r b e d a n d b r a i n damaged c h i l d r e n . J o u r n a l o f S p e c i a l E d u c a t i o n , 1969, 3, 4, 351-369. B u d o f f , M. M e a s u r i n g l e a r n i n g p o t e n t i a l : An a l t e r n a t i v e t o t h e t r a d i t i o n a l i n t e l l i g e n c e t e s t . S t u d i e s i n L e a r n i n g P o t e n t i a l , 1972, 3, 39. B u d o f f , M., & Corman, L. D e m o g r a p h i c and p s y c h o m e t r i c f a c t o r s r e l a t e d t o i m p r o v e d p e r f o r m a n c e o n t h e K o h s l e a r n i n g - p o t e n t i a l p r o c e d u r e . A m e r i c a n J o u r n a l o f M e n t a l D e f i c i e n c y , 1974 , 78_, 5 , 578-585. B u d o f f , M., & G o t t l i e b , J . S p e c i a l c l a s s EMR c h i l d r e n m a i n s t r e a m e d : A s t u d y o f an a p t i t u d e ( l e a r n i n g p o t e n t i a l ) X t r e a t m e n t i n t e r a c t i o n . A m e r i c a n J o u r n a l o f M e n t a l D e f i c i e n c y , 1976, 81. , 1-11. B u r k s , H.F., & B r u c e , P. The c h a r a c t e r i s t i c s o f p o o r a n d g o o d r e a d e r s a s d i s c l o s e d b y t h e WISC. J o u r n a l o f E d u c a t i o n a l P s y c h o l o g y , 1955 4_6, 7, 488-493. C a t r o n , D.W., & C a t r o n , S.S. WISC-R v s WISC: a c o m p a r i s o n w i t h e d u c a b l e m e n t a l l y r e t a r d e d c h i l d r e n . J o u r n a l o f S c h o o l P s y c h o l o g y , 1977 , 15_, 3 , 264-266. C o h e n , J . T h e f a c t o r i a l s t r u c t u r e o f t h e WISC a t a g e s 7-6, 10-6, and 13-6. J o u r n a l o f C o n s u l t i n g P s y c h o l o g y , 1959, 23, 285-299. C r o n b a c h , L . J . E s s e n t i a l s o f P s y c h o l o g i c a l T e s t i n g (2nd e d . ) . New Y o r k : H a r p e r , 1960. D e r n e r , G.F., A b o r n , M., & C a n t n e r , A.H. The r e l i a b i l i t y o f t h e W e c h s l e r - B e l l v u e s u b t e s t s and s c a l e s . J o u r n a l o f C o n s u l t i n g P s y c h o l o g y , 1950, L4, 172-179. . 68 E s t e s , W.K. L e a r n i n g t h e o r y a n d i n t e l l i g e n c e . Amer i c a n P s y c h o l o g i s t , 1974, 29_, 740-749. F e r g u s o n , G.A. S t a t i s t i c a l a n a l y s i s i n p s y c h o l o g y a n d e d u c a t i o n . New Y o r k : M c G r a w - H i l l Book Company, 1981. F e u e r s t e i n , R. The D y n a m i c A s s e s s m e n t o f R e t a r d e d P e r f o r m e r s : T h e L e a r n i n g P o t e n t i a l A s s e s s m e n t D e v i c e , T h e o r y , I n s t r u m e n t s , a n d T e c h n i q u e s . B a l t i m o r e : U n i v e r s i t y P a r k P r e s s , 1979. F e u e r s t e i n , R., M i l l e r , R., R a n d , Y., & M o g e n s , R . J . C a n e v o l v i n g t e c h n i q u e s b e t t e r m e a s u r e c o g n i t i v e c h a n g e ? J o u r n a l o f S p e c i a l E d u c a t i o n , 1981, J L 5 , 201-219. F o l m a n , R., & B u d o f f , M. L e a r n i n g p o t e n t i a l a n d v o c a t i o n a l a s p i r a t i o n s o f r e t a r d e d a d o l e s c e n t s . E x c e p t i o n a l C h i l d r e n , 1971, 3 9 , 121-130. Gagne, R.M. T h e c o n d i t i o n s o f l e a r n i n g ( 2 n d e d . ) . New Y o r k : H o l t , R i n e h a r t & W i n s t o n , 1970. G i r o n d a , R . J . A c o m p a r i s o n o f WISC and WISC-R r e s u l t s o f u r b a n e d u c a t i o n a l l y m e n t a l l y r e t a r d e d s t u d e n t s . P s y c h o l o g y i n t h e S c h o o l s , 1977, 1 4 , 3, 271-275. G l a s s , G.V. & S t a n l y , J . C . S t a t i s t i c a l m e t h o d s i n e d u c a t i o n and p s y c h o l o g y . Englewood C l i f f s : P r e n t i c e - H a l l , 1970. H a l e , R.L. T h e WISC-R a s a p r e d i c t o r o f WRAT p e r f o r m a n c e . P s y c h o l o g y i n t h e S c h o o l s , 1978 , 15., 2 , 172-175. Hardy, J.B., W e l c h e r , D.W., M e l l i t s , E.D., & Kagan, J . P i t f a l l s i n t h e m e a s u r e m e n t o f i n t e l l i g e n c e : A r e s t a n d a r d i n t e l l i g e n c e t e s t s v a l i d i n s t r u m e n t s f o r m e a s u r i n g t h e i n t e l l e c t u a l p o t e n t i a l o f u r b a n c h i l d r e n . T he J o u r n a l o f P s y c h o l o g y , 1976 , 94 , 43-45 . I r w i n , D.O. R e l i a b i l t y o f t h e W e c h s l e r I n t e l l i g e n c e S c a l e f o r C h i l d r e n . J o u r n a l o f E d u c a t i o n a l Measurement, 1966, 3_, 4, 289-292. Kaufman, A.S. F a c t o r a n a l y s i s o f t h e WISC-R a t 11 age l e v e l s b etween 6 1/2 and 16 1/2 y e a r s . J o u r n a l o f C o n s u l t i n g a n d C l i n i c a l P s y c h o l o g y , 1975 , 43_, 135-147. Kaufman, A . S . I n t e l l i g e n t T e s t i n g w i t h t h e WISC-R. New Y o r k : J o h n W i l e y and Sons, 1979. K r a t o c h w i l l , T.R. T h e movement o f p s y c h o l o g i c a l e x t r a s i n t o a b i l i t y a s s e s s m e n t . J o u r n a l o f S p e c i a l E d u c a t i o n , 1977 , 11 , 299-311. L a z a r u s , R.S. & E r i c k s o n , C.W. E f f e c t s o f f a i l u r e s t r e s s u p o n s k i l l e d p e r f o r m a n c e . J o u r n a l o f E x p e r i m e n t a l P s y c h o l o g y , 1952, 43, 100-105. . 69 Lomba r d , T . J . , & R i e d e l , R.G. A n a n a l y s i s o f t h e f a c t o r s t r u c t u r e o f t h e WISC-R a n d e f f e c t o f c o l o r o n t h e C o d i n g s u b t e s t . P s y c h o l o g y i n t h e S c h o o l s , 1978, 1_5, 2 , 176-179. L y l e , J . G . , & Goyen, J . P e r f o r m a n c e o f r e t a r d e d r e a d e r s on t h e WISC and e d u c a t i o n a l t e s t s . J o u r n a l o f Abnormal P s y c h o l o g y , 1969, 74, 1, 102-112. L y l e , J.G., & J o h n s o n , E.G. A n a l y s i s o f WISC C o d i n g : 3. w r i t i n g and c o p y i n g s p e e d , a n d m o t i v a t i o n . P e r c e p t u a l a n d M o t o r S k i l l s , 1973 , 36_, 211-214. M c l e o d , J . A c o m p a r i s o n o f WISC s u b t e s t s c o r e s o f p r e a d o l e s c e n t s u c c e s s f u l and u n s u c c e s s f u l r e a d e r s . A u s t r a l i a n J o u r n a l o f P s y c h o l o g y , 1965, 17, 3, 220-228. M a t a r r a z z o , R.G., W i e n s , A.N., M a t a r r a z z o , J.D., & Manaugh, T . S . T e s t - r e t e s t r e l i a b i l t y o f t h e WAIS i n a n o r m a l p o p u l a t i o n . J o u r n a l o f C l i n i c a l P s y c h o l o g y , 1 97 3 , 2 9 , 194-197. M a x w e l l , A . E . A f a c t o r a n a l y s i s o f t h e WISC. B r i t i s h J o u r n a l o f E d u c a t i o n a l P s y c h o l o g y , 1959 , 29_, 237-241 . M e r c e r , C . S t u d e n t s w i t h l e a r n i n g d i f f i c u l t i e s ( 2 n d e d . ) . Columbus, O h i o : C h a r l e s E. M e r r i l l P u b l i s h i n g Company, 1983. N a l v e n , F.B., & P u l e o , V. R e l a t i o n s h i p b e t w e e n D i g i t S p a n a n d c l a s s r o o m d i s t r a c t i b i l i t y i n e l e m e n t a r y s c h o o l c h i l d r e n . J o u r n a l o f C l i n i c a l P s y c h o l o g y , 1968 , 24_, 85-87 . OWMAR One way m u l t i v a r i a t e a n a l y s i s o f v a r i a n c e c o m p u t e r p r o g r a m . U n i v e r s i t y o f B r i t i s h C o l u m b i a . Q u e r e s h i , M.Y. P r a c t i c e e f f e c t s on t h e WISC s u b t e s t s c o r e s a n d IQ e s t i m a t e s . J o u r n a l o f C l i n i c a l P s y c h o l o g y , 1 968 , 24, 79-85. R a s k i n , L.M., B l o o m , A . S . , K l e e , S.H., & R e e s e , A. T h e a s s e s s m e n t o f d e v e l o p m e n t a l l y d i s a b l e d c h i l d r e n w i t h t h e W I S C - R , B i n e t a n d o t h e r t e s t s . J o u r n a l o f C l i n i c a l P s y c h o l o g y , 1978 , 3_4, 1, 111-114. R o s s , A.O. L e a r n i n g D i s a b i l i t y : The U n r e a l i z e d P o t e n t i a l . New Y o r k : M c G r a w - H i l l , 1977. R o y e r , F . L . I n f o r m a t i o n p r o c e s s i n g o f v i s u a l f i g u r e s i n t h e D i g i t S ymbol s u b s t i t u t i o n t a s k . J o u r n a l o f E x p e r i m e n t a l P s y c h o l o g y , 1971,- 87, 3, 335-342. R u g e l , R.P. WISC s u b t e s t s c o r e s o f d i s a b l e d r e a d e r s : A r e v i e w w i t h r e s p e c t t o B a n n a t y n e ' s r e c a t e g o r i z a t i o n . J o u r n a l o f L e a r n i n g D i s a b i l i t i e s , 1974 , ]_, 1 , 48-55 . . 70 S a t t l e r , J.M. A s s e s s m e n t o f C h i l d r e n ' s I n t e l l i g e n c e a n d S p e c i a l A b i l i t i e s ( 2 n d e d . ) . B o s t o n : A l l y n & Bacon, I n c . , 1982 . S m i t h , M.D. S t a b i l i t y o f WISC-R s u b t e s t p r o f i l e s f o r l e a r n i n g d i s a b l e d c h i l d r e n . P s y c h o l o g y i n t h e S c h o o l s , 1 978 , 1_5, 1, 4-7. S o l l y , D.C. B r i e f r e p o r t o n t h e WISC-R: A c o m p a r i s o n o f WISC and WISC-R s c o r e s o f m e n t a l l y r e t a r d e d and g i f t e d c h i l d r e n . J o u r n a l o f S c h o o l P s y c h o l o g y , 1977, 15, 3, 255-258. T a b a c h n i c k , B.G. T e s t s c a t t e r o n t h e WISC-R. J o u r n a l o f L e a r n i n g D i s a b i l i t i e s , 1979 , 1_2, 9 , 626-628. T h o r n d i k e , E . L . M e a s u r e m e n t o f i n t e l l i g e n c e . T e a c h e r ' s C o l l e g e , Columbus U n i v e r s i t y , New Y o r k , 1926. T h u r s t o n e , L . L . P r i m a r y m e n t a l a b i l i t i e s . P s y c h o m e t r i c Monographs, 1938, No. 1. Tuma, J.M., & Appelbaum, A.S. R e l i a b i l i t y and p r a c t i c e e f f e c t s o f WISC-R IQ e s t i m a t e s i n a n o r m a l p o p u l a t i o n . E d u c a t i o n a l and P s y c h o l o g i c a l Measurement, 1980 , 4_0_, 671-678. V a n c e , . H . B . , S i n g e r , M.G., & E n g i n , A.W.. WISC-R s u b t e s t d i f f e r e n c e s i n l e a r n i n g d i s a b l e d c h i l d r e n a n d y o u t h . J o u r n a l o f C l i n i c a l P s y c h o l o g y , 1980 , 3_6, 4, 953-957 . W e c h s l e r , D. M a n u a l f o r t h e W e c h s l e r I n t e l l i g e n c e S c a l e f o r C h i l d r e n - R e v i s e d . New Y o r k : The P s y c h o l o g i c a l C o r p o r a t i o n , 1974 . Worme1i, T. B r i t i s h C o l u m b i a Q u i c k I n d i v i d u a l E d u c a t i o n a l T e s t . V a n c o u v e r : U n i v e r s i t y o f B r i t i s h C o l u m b i a P r e s s , 1982 . . 71 APPENDIX C l a s s i f i c a t i o n o f S u b j e c t s by t h e 1 t h D i s c r i m i n a n t F u n c t i o n ( N o r m a l s - 1 : D i s a b l e d - 2 ) S u b j e c t G r o u p s Number 1 2 22 -12. 066 27 -9. 673 29 -1. 832 33 -0. 744 35 -0. 642 26 -0. 491 24 -0. 445 38 0. 053 32 0. 656 23 0. 676 36 0. 855 30 0. 936 34 1. 910 37 3. 924 28 5. 957 25 6. 788 31 7 . 503 7 32. 147 17 32. 322 12 32. 896 6 33. 751 10 34. 748 21 35. 511 2 36. 662 9 37. 123 5 36. 155 8 38. 532 3 40. 377 18 42. 120 1 42. 246 16 42. 885 13 42. 972 11 45. 565 4 46. 343 20 49. 919 14 51. 231 15 52. 768 19 53. 580 1 t h d i s c r i m i n a n t f u n c t i o n ^ 11.7586 *Note S t u d e n t numbers 1 t o 21 r e p r e s e n t e d s t u d e n t s f r o m n o r m a l g r o u p . S t u d e n t numbers 2 2 t o 3 2 r e p r e s e n t e d l e a r n i n g d i s a b l e d g r o u p . I f w e i g h t e d s c o r e e x c e e d e d 1 t h d i s c r i m i n a n t f u n c t i o n s t u d e n t s were c l a s s i f i e d as n o r m a l ( g r o u p 1 ) . "@en . "Thesis/Dissertation"@en . "10.14288/1.0096453"@en . "eng"@en . "Special Education"@en . "Vancouver : University of British Columbia Library"@en . "University of British Columbia"@en . "For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use."@en . "Graduate"@en . "An investigation of the Wisc-R coding subtest as a measure of learning potential"@en . "Text"@en . "http://hdl.handle.net/2429/25434"@en .