One of the primary advantages of a repeated-measures design, compared to an independent-measures design, is that it reduces the overall variability by removing variance caused by individual differences. The following data are from a research study comparing three treatment conditions.
a. Assume that the data are from an independentmeasures study using three separate samples, each with n = 6 participants. Ignore the column of P totals and use an independent-measures ANOVA with a = .05 to test the significance of the mean differences.
b. Now assume that the data are from a repeatedmeasures study using the same sample of n = 6 participants in all three treatment conditions. Use a repeated-measures ANOVA with a = .05 to test the significance of the mean differences.
c. Explain why the two analyses lead to different conclusions.

Transcribed Image Text:

Treatment 1 Treatment 2 Treatment 3 P 12 27 824N=18 21G=108 12 ΣΧ2=800 4 7 15 M=4 T=24 SS = 42 M=6 T=36 SS=28 M=8 T=48 SS=34