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The effect of bin order on waste sorting behaviour Quemado, Diego; Chang, Ching Hsuan Jason; Tang, Julian Apr 28, 2015

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 UBC Social Ecological Economic Development Studies (SEEDS) Student ReportChing Hsuan Jason Chang, Diego Quemado, Julian TangThe Effect of Bin Order on Waste Sorting BehaviourPSYC 321April 28, 201512761876University of British Columbia Disclaimer: “UBC SEEDS Program provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or a SEEDS team representative about the current status of the subject matter of a project/report”. UBC Social Ecological Economic Development Studies (SEEDS) Student ReportChing Hsuan Jason Chang, Diego Quemado, Julian TangThe Effect of Bin Order on Waste Sorting BehaviourPSYC 321April 28, 201512761876University of British Columbia Disclaimer: “UBC SEEDS Program provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or a SEEDS team representative about the current status of the subject matter of a project/report”. 1 The Effect of Bin Order on Waste Sorting Behaviour  Team Green: Diego Quemado, Ching Hsuan Jason Chang, and Julian Tang       EXECUTIVE SUMMARY To test how the order of bins at waste disposal stations impacts sorting behaviour, 180 participants were observed disposing waste at a restaurant in three conditions of different bin orders, with 60 participants in each condition. The first condition had the bin order of: Compost, Garbage, and Recycle. The second condition had the bin order of: Garbage, Compost, and Recycle. The third condition had the bin order: Recycle, Compost, and Garbage. Waste sorting accuracy was measured as the percentage of the total number of items that each participant sorted into the correct bins, recorded independently by three observers. The means of the three conditions were 60.43% for condition 1, 66.50% for condition 2, and 59.76% for condition 3. Inter-rater reliability was high, with 81% of data collected in agreement. A one-way ANOVA was used to find any significant differences between the three means and independent samples t-tests were used to find any significant differences between any two conditions. All statistical tests found no significant differences, suggesting that the position of the garbage bin at waste disposal stations does not matter, and that future studies are needed to further explore the impact of bin order on waste sorting behaviour.  Keywords waste disposal, waste sorting behaviour, recycling, garbage, compost, bin order, environmental psychology      Research Question and Hypothesis The research question being asked in this study is: How does the order of bins impact sorting? This questions aims to determine if changing the bin order from left to right will affect the waste sorting behaviour of people when they throw their trash. The hypothesis is that sorting accuracy (the percentage of correct disposals per participant) will be highest when the bin order from left to right is: Recycle, Compost, then Garbage (Condition 1). We hypothesized that this bin order would produce the best results because it is the traditional way of organizing the bins. It was the original bin order in that location, and the most commonly used bin order around the university campus. We believed that people were accustomed to this bin order; therefore it would be easiest for them to sort out the trash in this condition.   METHOD       Participants      The participant population included students, faculty, visitors, and staff of the University of British Columbia who ate in Mercante Restaurant (an Italian Restaurant) at the Ponderosa Building (Appendix D). There were a total of 180 participants in the study (n = 180). It is assumed that Mercante restaurant provided a neutral environment (unlike the CIRS building) with no potential biases towards positive recycling behaviour because of the  2 fact that it is a restaurant open to everyone. It was also ideal because the garbage, recycling, and compost bins of the waste disposal station had no identifying characteristics, such as colour or shape of the bin, aside from the signs themselves (Appendix A).     Conditions    There were three conditions in this study. The first condition had the bin order of: Compost, Garbage, and Recycle. The second condition had the bin order of: Garbage, Compost, and Recycle. The third condition had the bin order: Recycle, Compost, and Garbage. The labels of each bin were changed (as seen in Appendix A) based on the condition being tested. The three conditions were observed on three consecutive days in a single location (Mercante Restaurant in the Ponderosa Building). The only factor that changed throughout the conditions was the label of the bins. Everything else, including the location of the waste station in the restaurant, the shape of the bins, and the colour of the bins remained constant. There were a total of 60 participants in each condition.       Measures     This is an experimental study, with the independent variable being the order of bins and the dependent variable being the sorting accuracy (percentage of correct disposals per participant) in each condition. For each participant, we calculated the number of correct throws he/she had divided by his/her total amount of throws (Appendix E). We therefore had 60 individual percentages for each condition (Appendix B). The experimenters compared their observations for inter-rater reliability. Since it was an observational study that had no potential risks to participants, no oral consent was needed from participants. A One-way ANOVA was used to determine if there are any significant differences between the three means (Appendix C). In addition to this, we tested if there were any significant differences between any of the two conditions using the Independent Samples t-test (Appendix C).        Procedure  The study was conducted during three separate days in the month of March, between the times of 12pm and 3pm. Waste sorting accuracy was measured as the percentage of the total number of items that each participant sorted into the correct bins.         In order to discern the optimal bin order, in each of the three separate days, the researchers rearranged the bin order. On the first day, from left to right, the bins were ordered recycle, followed by compost, then garbage. This was the default bin order, the usual order the bins in the restaurant, without us making any changes. On the second day, the bins were rearranged with garbage occupying the leftmost bin, followed by compost, and then recycle. On the last day, the compost bin occupied the leftmost spot, followed by garbage, and then recycle bin.         Following the last day of observation, the researchers then compared and contrasted each individual data collected, and subsequently tested for inter-rater reliability. The inter-rater reliability between the three data sets were high, with 81% of the data gathered agreeing with each other. The dissimilar data was then discarded, and filled with additional observations in order to achieve the desired total of 180 agreed-upon observations.            3 RESULTS Based on our observations, we found that the second condition (garbage, compost, recycle) yielded the highest sorting accuracy of 66.50%. This was followed by the first condition (recycle, compost, garbage), which yielded a sorting accuracy of 60.43%, while the third condition (compost, garbage, recycle) generated the lowest sorting accuracy of 59.76% (Appendix F). Conducting a one-way ANOVA between the three conditions yielded an F statistic of 0.434, with a p-value of 0.655, as well as having two degrees of freedom. Furthermore, the one-way ANOVA led to the conclusion that the group means did not yield any statistically significant differences, because the p-value was greater than 0.05. As such, post hoc ANOVA tests are not required, since the results are not statistically significant. From conducting independent samples t-tests, we determined that though the second condition yielded the best results, when compared to the first condition, the difference is not statistically significant, with a p-value of 0.448. Similarly, comparing the second condition to the third one yielded a p-value of 0.410, which means the difference is also not statistically significant. Lastly, the difference between the first and third conditions was also not statistically significant, with a p-value of 0.934. Because the p-values were not less than or equal to 0.05, in all three conditions we concluded that there are no significant differences. These findings further support the conclusions drawn up by the one-way ANOVA, in that there are no statistically significant differences between any of the three conditions.         Due to the nature of the way in which our observations were coded, where one correct throw out of one yielded a score of 100%, and where one correct throw out of two would similarly yield a score of 50%, the standard deviation between points were high. The first condition yielded a standard deviation of 43.38, the second condition, a standard deviation of 44.47, and the third condition, a standard deviation of 45.18 (Appendix F). This shows that the differences between each observation were large, with the third condition producing the largest differences between correct throws. The researchers would like to note that though the standard deviation between points may be large, it does not disrupt the data, as it is a natural occurrence due to the way the data was coded.  DISCUSSION While the second condition yielded the best sorting accuracy, and therefore seemed to be optimal order for waste sorting, further analysis of the results revealed that none of the three conditions are any better than the others in terms of statistically significance, as neither one produced a p-value less than or equal to 0.05. This was determined through the use of three separate t-tests, as well as the use of a One-way ANOVA between subjects. As such, though the second condition produced the best sorting accuracy relative to the other two conditions, we cannot make recommendations to use this order due to the lack of statistical significance.         One underlying reason for this may the lack of observations. As we only observed a total of three conditions over three days, increasing the number of observations and conditions may strengthen the reliability of our results. Although this may increase the study’s reliability, we predict that significant results may not yield any significant differences even with more participants. This is due to the law of small and large numbers. Because the statistical difference with a small set of conditions is not high, using a larger set of observations would likely just amplify the effect of averages converging into a smaller  4 range of numbers. In the end, this would strengthen the reliability of our study, but would most likely not produce any more significant results, as per the law of large numbers.         Although we tried to minimize possible confounding variables that may affect our results in conducting our study, we recognize some that may still have skewed our observations. The first possible confounding variable is that people may have noticed that we were observing them throwing trash, generating an observer’s effect. Because of the nature of our study, we had to observe our subjects relatively closely in order to discern how accurate each individual throws were. This may have made us too obvious to the individuals we were observing, and thus, made them more mindful of how they dispose of their garbage. This may be remedied by observing from a further distance, but may reduce the observers’ ability to collect accurate results. A second possible limitation to our study is that because our study entailed switching bin positions around, it may have created a shock-and-awe effect, in that people may have become keenly aware that bin positions have been changed, thus drawing more attention to it. Because UBC arranges bins throughout campus in a certain order, people may have become accustomed to throwing trash in certain bins without paying much attention to it. This practice effect may be the biggest limitation to our study, because there is little that may be done to curb this effect. Lastly, a third possible limitation to our study may be that people are simply uninformed as to which bins certain objects belong to. From what we have observed, a common example of this is the coffee cup. The coffee cups offered in Mercante are made up of three main components, the cup itself, its lid, and its sleeve. Though the sleeve should be disposed of in the compost bin, the lid and the cup should be disposed of in the recycling bin. From our observations, we noticed that most people either separated the lid only, and disposed of the cup and sleeve into the compost bin, or outright disposed of the whole thing into the compost bin. In this example, it may be due to a lack of knowledge rather that blatant disregard for sorting trash that people incorrectly dispose of coffee cups. In order to limit this effect, we suggest that signs be erected to make people more aware of these details regarding waste disposal.         For future studies, we first recommend, exploring all six possible bin combinations. For our study, we only explored three conditions, as we had only sought to manipulate the garbage bin, placing it in every possible position. Exploring all six possible bin combinations would likely discern the optimal bin sorting order.  Another recommendation is to record the waste disposal accuracy of each bin. In our study, we only observed whether an individual disposed of anything into the corresponding correct bin, then totalled his/her score to give us the overall waste sorting accuracy percentage. Recording waste disposal accuracy for each bin would further the understanding of waste disposal, and may also give an indication as to where or how most people dispose of waste incorrectly.           Recommendations for UBC      Because we found no significant differences between the three bin orders we tested, we can only recommend for UBC to conduct further studies, exploring all six possible bin orders. Since our study looked at the three possible positions of the garbage bin and found no significant differences, we can suggest that the position of the garbage bin does not matter for optimizing waste sorting behaviour. Therefore, future studies should focus more on how the positions of the recycling and compost bins affect sorting behaviour. Another  5 recommendation is to record the waste disposal accuracy of each bin, to see if people dispose of waste most incorrectly to any of the bins in particular. Knowing the most conducive order of bins for accurate recycling behaviour will contribute to the University’s sustainability goals of becoming a “Zero Waste” campus. Furthermore, while making our observations, we noticed that the UBC waste disposal staff themselves did not separate the compost, recycling, and garbage from one another when changing the garbage bags from the bins we were observing, but rather mixed everything together. For UBC to reach its goals of diverting more and more waste from the landfill, it needs to ensure the Waste Management Staff themselves are practicing good waste sorting behaviour through training and education. We recommend that the education be extended also to students, to both promote and educate about proper waste disposal, because it was evident, as in the coffee cup example, that many students, while trying to correctly sort their waste, simply did not know what kind of waste belongs in which bin. Education programs can help address this problem and move UBC towards becoming a truly “Zero Waste” campus.                                         6 Appendix A. Images of the Three Conditions in the Study (Mercante Restaurant)  Condition 1. Bin order from left to right: Recyclables, Compost, then Garbage.   Condition 2. Bin order from left to right: Garbage, Compost, then Recyclables.  Condition 3: Bin order from left to right: Compost, Garbage, then Recyclables.   7 Appendix B. Observational Data Recorded via Microsoft Excel during the experiment (An ‘x’ represents a wrong throw, while a ‘c’ represents a right throw.)  Condition 1. Bin order from left to right: Recyclables, Compost, then Garbage.   Condition 2. Bin order from left to right: Garbage, Compost, then Recyclables.                      8  Condition 3. Bin order from left to right: Compost, Garbage, then Recyclables.                                                9 Appendix C. SPSS Statistical Data Analysis  Below is a One-Way ANOVA Analysis showing that there are no statistically significant differences between the means of the three conditions. No post-hoc analysis was done due to the fact that there were no statistically significant results.     Below is an Independent Samples t-test comparing between Condition 1 and Condition 2.   10 Below is an Independent Samples t-test comparing between Condition 2 and Condition 3.     Below is an Independent Samples t-test comparing between Condition 1 and Condition 3.          11 Appendix D. Full image of Mercante Restaurant in the Ponderosa Building at UBC          Appendix E. Summary of Independent and Dependent Variable   • Independent Variable: Order of bins from left to right (e.g. Recycle, Compost, then Garbage)  • Dependent Variable: Percentage of correct disposals per participant  = Number of correct throws per participant / Total amount of throws per participant (e.g. Throwing a water bottle to Recyclables is 1 correct. Throwing a pizza crust to Garbage is 1 wrong. This hypothetical participant would get ½ or 50%.)                                                 12 Appendix F. Summary of Statistical Results              Mean Standard Deviation N Condition 1 60.433 43.38 60 Condition 2 66.533 44.47 60 Condition 3 59.766 45.18 60 Total 62.244 44.21 180 Conditions: 1-2 1-3 2-3 P-value .448 .934 .410 

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