RISKY SHIFT: LAB REPORT WRITE-UP Week 7 Practical

LECTURE PRACTICAL WEEK 1 WEEK 2 WEEK 3 WEEK 4 WEEK 5 WEEK 6 WEEK 7 RISKY SHIFT WEEK 7 PRACTICAL LECTURE PRACTICAL WEEK 1 NO LECTURE NO PRACTICAL WEEK 2 NONPARAMETRICS 1 1ST PRACTICAL WEEK 3 NONPARAMETRICS 2 1ST ANALYSIS WEEK 4 1ST ANALYSIS + PROBLEMS 1 WEEK 5 SAMPLING DISTRIBUTIONS 2ND PRACTICAL WEEK 6 HYPOTHESIS TESTING 2ND ANALYSIS + SOLUTIONS 1 WEEK 7 RELATED T-TEST 2ND ANALYSIS + PROBLEMS 2 WEEK 8 INDEPENDENT T-TEST 3RD PRACTICAL WEEK 9 INDEPENDENT ANOVA 3RD ANALYSIS + SOLUTIONS 2 WEEK 10 DEPENDENT ANOVA 3RD ANALYSIS + PROBLEMS 3

BY THE END OF THE SESSION, YOU SHOULD BE ABLE TO: RISKY SHIFT LEARNING OUTCOMES BY THE END OF THE SESSION, YOU SHOULD BE ABLE TO: Understand the way in which the practical reports will be marked and what you have to do to do well! Learn to calculate the Wilcoxon test by hand. Tackle an additional problem sheet which should help you understand the principles behind non-parametric tests more fully. Clarify any additional problems that you may have regarding this lab report with your friendly neighbourhood demonstrators.

2 12 20 20 20 20 6 IV and DV included, precise, concise RISKY SHIFT PRACTICAL WRITE-UP 2 IV and DV included, precise, concise TITLE 12 Maximum 150 words, summary of all sections ABSTRACT 20 Clear structure leading to experimental rationale INTRODUCTION Evidence of extra reading, beyond the handouts 20 METHOD Sufficient information to replicate the study Participants, materials, design, procedure 20 Clear and logical descriptive and inferential stats RESULTS Well designed figures related to the findings 20 Summary of main results, relating to introduction DISCUSSION Evaluation of study, suggestions for future 6 REFERENCES APA formatted, consistent with references in text APPENDICIES Handouts, SPSS printouts, workings out…

DOWNLOAD AND SAVE THE FILE ‘WILCOXONBYHAND’ RISKY SHIFT WILCOXON BY HAND DOWNLOAD AND SAVE THE FILE ‘WILCOXONBYHAND’ First, you should be able to complete the smaller exercise on the Wilcoxonbyhand document, and check your workings using ‘wilcoxonbyhand_done’ There is an addition exercise which provides you with the steps to carry out a Wilcoxon by hand on the Risky Shift data using Excel. Taking a look at this exercise should improve your Excel skills if nothing else. DO NOT PANIC ABOUT GETTING THROUGH BOTH EXERCISES. FOCUS ON UNDERSTANDING HOW TO DO WILCOXON BY HAND. DOWNLOAD AND SAVE THE FILE ‘WILCOXONBYHAND_DONE’

Follow the sheet to complete a Wilcoxon for the small data set. RISKY SHIFT WILCOXON BY HAND Follow the sheet to complete a Wilcoxon for the small data set. RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test Here’s a reminder of how to do the Wilcoxon ranking from the lecture…

BY THE END OF THE SESSION, YOU SHOULD BE ABLE TO: RISKY SHIFT LEARNING OUTCOMES BY THE END OF THE SESSION, YOU SHOULD BE ABLE TO: Understand the way in which the practical reports will be marked and what you have to do to do well! Learn to calculate the Wilcoxon test by hand. Tackle an additional problem sheet which should help you more fully understand the principles behind non-parametric tests. Clarify any additional problems that you may have regarding this lab report with your friendly neighbourhood demonstrators.

RISKY SHIFT YOUR CHOICE YOU HAVE THE REST OF THE SESSION TO FOCUS ON WHAT YOU THINK YOU NEED TO IMPROVE YOUR UNDERSTANDING LAB REPORT TESTS BY HAND NONPARAMETRICS Make sure you are happy with your interpretation of the SPSS output in relation to the three experimental hypotheses ,and make sure you know what needs to go into your lab report to get the best marks. Try working through the second Wilcoxon analysis using the ‘riskyinexcel’ workbook and compare your hand results with the results you obtained from SPSS. The brave could also try a Friedman’s test by hand using Graham’s guide. Download ‘problem5’ and start to work through the questions related to the forthcoming related t-test (as well as some problems relating to correlation and regression).

DOWNLOAD AND SAVE THE FILE ‘RISKYINEXCEL’ RISKY SHIFT WILCOXON BY HAND DOWNLOAD AND SAVE THE FILE ‘RISKYINEXCEL’ DOWNLOAD AND SAVE THE FILE ‘WILCOXONBYHAND’ There’s an awful lot of data here, so it’s probably best to focus on one of the hypotheses and take it slowly. Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test At the bottom of the sheet (and the separate Word file), there are instructions on how to calculate Wilcoxon using Excel.

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 1) CALCULATE THE DIFFERENCE BETWEEN D AND C SCORES IN (H) AND RETAIN THE SIGN. = CELLab- CELLcd

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 2) CALCULATE THE ABSOLUTE DIFFERENCE FOR (H) IN (J) =ABS (CELL)

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 3) COPY AND PASTE ID AND SCORE VALUES FROM COLUMN I AND J INTO COLUMN K AND L EDIT > COPY

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 4) SORT COLUMNS K AND L BY COLUMN L (RANKED DIFFERENCES) DATA > SORT > SORT BY We are doing this as an easy way to rank order the data, but we also need to keep track of whether these differences are positive or negative in the final analysis. Hence, each individual difference keeps its unique id code.

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 5) BEGINNING WITH THE FIRST NON-ZERO DIFFERENCE IN COLUMN N ASSIGN RANK SCORES STARTING AT 1

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 6) SCORES THAT SHARE THE SAME NON-ZERO DIFFERENCE MUST SHARE AVERAGE RANK IN COLUMN P The first 11 numbers all share a difference of 0.4, so they are all assigned the rank value of 6 (1+2+3+4+5+6+7+8+9+10+11/11 = 6)

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 7) TAKE THE SORTED ID VALUES FROM COLUMN K AND PASTE INTO COLUMN O 8) NOTE THAT IN COLUMN S, THE ORIGINAL SIGNED DIFFERENCES ARE ALREADY THERE

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 9) SORT COLUMNS O AND P BY COLUMN O (ASCENDING) DATA > SORT > SORT BY

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 10) COPY AND PASTE VALUES FROM COLUMN P OVER TO COLUMN U DATA > SORT > SORT BY

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 11) REINSTATE NEGATIVE VALUES WHERE APPROPRIATE

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test 12) SORT COLUMN U (ASCENDING)

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test Congratulations! You now have everything you need to finish the test! SUM NEGATIVE SUM POSITIVE 828 33 No. NEGATIVE No. POSITIVE TOTAL OBSERVATIONS 37 4 41 NOTE: This is exactly the same data produced by SPSS!

Congratulations! You now have everything you need to finish the test! RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test Congratulations! You now have everything you need to finish the test! SUM NEGATIVE SUM POSITIVE 828 33 No. NEGATIVE No. POSITIVE TOTAL OBSERVATIONS 37 4 41 We use the smaller of the sums (33) as our observed W. We use the total number of non-zero observations (41) as our df. Look up the critical value of W, taking into account N. If our obtained W is smaller than the critical value of W, we reject the null hypothesis and conclude that two groups do differ significantly.

RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test RISKY SHIFT WILCOXON BY HAND Q2: Is the average level of risk recorded in the PRE assessment different from the risk recorded in the GROUP assessment? RATINGS + WITHIN Ss + 2 GROUPS Wilcoxon test N = 41 Obtained W = 33 Critical W = 89 Obtained W < Critical W There is a statistically significant difference between the two groups Table only goes up to N = 25 but this is good enough (the critical value would be much bigger than 89 for an N = 41)