P6 7.0 8.0 9.5 24.5 4.5 5.5 6.75 M Sum (T) 27.0 33.0 40.5 100.5 17.5 17.5 19.375 SS Source SS df MS F Between Treat 15.25 2 7.625 305 Within 54.375 15 Subject 54.125 5 Error .25 10 0.025 Total 69.625 17 Next, I’ve decreased the first two participants’ scores by a constant amount and increased the last two participants’ scores by a constant amount. Because the interaction between participant and treatment is the same, the is unchanged. However, because the MSError means for the 6 participants are more different than before (greater individual differences), the increases. Nonetheless, the is the same, because those individual SSSubject F-ratio differences are removed from the error term. 2 grams 4 grams 6 grams P P1 1.0 2.0 3.0 6.0 P2 2.0 3.0 4.5 9.5 P3 4.0 5.0 6.0 15.0 P4 5.0 6.0 7.5 18.5 P5 7.0 8.0 9.0 24.0 P6 8.0 9.0 10.5 27.5 4.5 5.5 6.75 M Sum (T) 27.0 33.0 40.5 100.5 37.5 37.5 39.375 SS Source SS df MS F Between Treat 15.25 2 7.625 305 Within 114.375 15 Subject 114.125 5 Error .25 10 0.025 Total 129.625 17 SPSS for Repeated Measures ANOVA: G&W 458 First, enter as many columns (variables) as you have levels of your independent variable. Below left are the data, with each column containing scores for a particular level of the IV. For the analysis, choose from the General Linear Model->Repeated Measures… Analyze menu. Doing so will produce the window seen below right. Note that I’ve given the Factor Name (sleepdep) and the number of levels (3). Once I click on I would Add, click on the button. Define The next window that appears has all your variables on the left. I’ve moved the appropriate ones to the right, as seen below left. As was true for the independent groups ANOVA, you’d
P6 7.0 8.0 9.5 24.5 M 4.5 5.5 6.75 Sum (T) 27.0 33.0 40.5 100.5 SS 17.5 17.5 19.375 Source SS df MS F Between Treat 15.25 2 7.625 305 Within 54.375 15 Subject 54.125 5 Error .25 10 0.025 Total 69.625 17 Next, I’ve decreased the first two participants’ scores by a constant amount and increased the last two participants’ scores by a constant amount. Because the interaction between participant and treatment is the same, the MSError is unchanged. However, because the means for the 6 participants are more different than before (greater individual differences), the SSSubject increases. Nonetheless, the F-ratio is the same, because those individual differences are removed from the error term. 2 grams 4 grams 6 grams P P1 1.0 2.0 3.0 6.0 P2 2.0 3.0 4.5 9.5 P3 4.0 5.0 6.0 15.0 P4 5.0 6.0 7.5 18.5 P5 7.0 8.0 9.0 24.0 P6 8.0 9.0 10.5 27.5 M 4.5 5.5 6.75 Sum (T) 27.0 33.0 40.5 100.5 SS 37.5 37.5 39.375 Source SS df MS F Between Treat 15.25 2 7.625 305 Within 114.375 15 Subject 114.125 5 Error .25 10 0.025 Total 129.625 17 SPSS for Repeated Measures ANOVA: G&W 458 First, enter as many columns (variables) as you have levels of your independent variable. Below left are the data, with each column containing scores for a particular level of the IV. For the analysis, choose General Linear Model->Repeated Measures… from the Analyze menu. Doing so will produce the window seen below right. Note that I’ve given the Factor Name (sleepdep) and the number of levels (3). Once I click on Add, I would click on the Define button. The next window that appears has all your variables on the left. I’ve moved the appropriate ones to the right, as seen below left. As was true for the independent groups ANOVA, you’d
S.Ch13.docx