MEMORY PERSPECTIVES: DATA ANALYSIS Week 9 Practical

WEEK 9 PRACTICALMEMORY PERSPECTIVES WEEK 1 WEEK 2 WEEK 3 WEEK 4 WEEK 5 WEEK 6 WEEK 7 WEEK 8 WEEK 9 WEEK 10 LECTURE 1PRACTICAL NONPARAMETRICS 11 ST PRACTICAL NONPARAMETRICS 21 ST ANALYSIS SAMPLING DISTRIBUTIONS 1 ST ANALYSIS + PROBLEMS 1 HYPOTHESIS TESTING 2 ND PRACTICAL RELATED T-TEST 2 ND ANALYSIS + SOLUTIONS 1 INDEPENDENT T-TEST INDEPENDENT ANOVA DEPENDENT ANOVA 2 ND ANALYSIS + PROBLEMS 2 3 RD PRACTICAL 3 RD ANALYSIS + SOLUTIONS 2 3 RD ANALYSIS + PROBLEMS 3 NO LECTURENO PRACTICAL

LEARNING OUTCOMES BY THE END OF THE SESSION, YOU SHOULD BE ABLE TO: Produce a (very nice) graph in Excel which assists in the interpretation of the data. Use SPSS to test the second hypothesis in the memory perspectives practical and interpret the output. Use SPSS to test the first hypothesis in the memory perspectives practical and interpret the output. Make a start on writing up your RESULTS and DISCUSSION sections for your lab report. MEMORY PERSPECTIVES

RESULTS The first 2 columns show subject id and group membership. The last two columns show recall for LIST A (BURGLAR) and LIST B (BUYER). MEMORY PERSPECTIVES (Perspect 0 = BURGLAR; Perspect 1 = BUYER)

RESULTS In SPSS, Independent t-test may be found under analysis > compare means > independent-samples t test. Independent t-testINTERVAL + BETWEEN Ss + 2 GROUPS Q1: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST A (burglar relevant items)? MEMORY PERSPECTIVES

RESULTS SPSS would like to know what the test variables (DV) is. At the moment, we’re just interested in LIST A recall. We also need to define our ‘grouping variable’ (IV) which is BURGLAR (0) or BUYER (1). We have to tell SPSS that our first group is assigned to the number value 0 and the second group to the number value 1. Independent t-testINTERVAL + BETWEEN Ss + 2 GROUPS Q1: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST A (burglar relevant items)? MEMORY PERSPECTIVES

RESULTS Remember that Levene’s test assesses whether our two groups have equivalent variance. If Levene’s is NON-SIGNIFICANT we assume equality. Independent t-testINTERVAL + BETWEEN Ss + 2 GROUPS Q1: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST A (burglar relevant items)? With Levene’s F = 1.60, p =.207, we arrive at t(151) = 6.64, p <.001. MEMORY PERSPECTIVES

RESULTS In SPSS, Independent t-test may be found under analysis > compare means > independent-samples t test. Independent t-testINTERVAL + BETWEEN Ss + 2 GROUPS Let’s repeat this exercise for the second hypothesis. MEMORY PERSPECTIVES Q2: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST B (home-buyer relevant items)?

RESULTS Now, we’re interested in LIST B (buy_fea) recall rather than LIST A (burg_fea) recall, so switch these test variables around. Everything else can stay as is. Independent t-testINTERVAL + BETWEEN Ss + 2 GROUPS MEMORY PERSPECTIVES Q2: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST B (home-buyer relevant items)?

RESULTS Once again, Levene’s test comes through for us, supporting equal variance between the burglars and the buyers. Independent t-testINTERVAL + BETWEEN Ss + 2 GROUPS With Levene’s F = 1.12, p =.291, we arrive at t(151) = -3.90, p <.001. MEMORY PERSPECTIVES Q2: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST B (home-buyer relevant items)?

RESULTS Q2: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST B (home-buyer relevant items)? Q1: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST A (burglar relevant items)? If you’re hungry for the stats, and wanted to spit out both SPSS output to Q1 and Q2, then all you have to do is define multiple test variables… So, everything’s significant, but what are the directions of these effects? Excel to the rescue. MEMORY PERSPECTIVES DOWNLOAD AND SAVE THE FILE ‘MEMPER_ANALYSIS’

RESULTS DOWNLOAD AND SAVE THE FILE ‘MEMPER_INEXCEL’ To calculate mean: AVERAGE(cell ab :cell cd ) To calculate standard deviation: STDEV(cell ab :cell cd ) To calculate standard error: =STDEV(cell) / sqrt ( no. observations ) To start graphing: Select means and labels THIS SHEET CONTAINS THE SAME DATA AS IN SPSS MEMORY PERSPECTIVES

RESULTS COLUMN MEMORY PERSPECTIVES

RESULTS SELECT SERIES IN COLUMNS > NEXT MEMORY PERSPECTIVES

RESULTS MODIFY MEMORY PERSPECTIVES

RESULTS DOUBLE CLICK ONE SET OF BARS (BURGLARS ARE HIGHLIGHTED) MEMORY PERSPECTIVES

RESULTS ADD CUSTOM +/- STANDARD ERROR RELATED TO THOSE BARS MEMORY PERSPECTIVES

RESULTS REPEAT FOR THE OTHER SET OF BARS (BUYERS ARE HIGHLIGHTED) MEMORY PERSPECTIVES

RESULTS Q2: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST B (home- buyer relevant items)? Q1: Do ‘BURGLARS’ and ‘BUYERS’ have different levels of recall for LIST A (burglar relevant items)? LIST A BURGLARS > BUYERS MEMORY PERSPECTIVES LIST B BURGLARS < BUYERS What implications do these two hypotheses have for the memory perspectives account?

LEARNING OUTCOMESMEMORY PERSPECTIVES BY THE END OF THE SESSION, YOU SHOULD BE ABLE TO: Produce a (very nice) graph in Excel which assists in the interpretation of the data. Use SPSS to test the second hypothesis in the memory perspectives practical and interpret the output. Use SPSS to test the first hypothesis in the memory perspectives practical and interpret the output. Make a start on writing up your RESULTS and DISCUSSION sections for your lab report.

MEMORY PERSPECTIVES THERE IS NO PRACTICAL SESSION IN WEEK 10 CLARIFY ANY OUTSTANDING ISSUES YOU HAVE WITH YOUR TUTORS NOW...

DISCUSSION GET TOGETHER IN GROUPS OF THREE OR FOUR AND REFLECT ON TODAY’S EXPERIENCE USING THE FOLLOWING QUESTIONS What are the combined factors that justify this statistical test? Are there any interesting observations to be made from the data? Could I have made one- tailed hypotheses? How would this have changed the p value? MEMORY PERSPECTIVES