One of the advantages of a repeated-measures design is that it removes the individual differences from the error variance and increases the likelihood of rejecting the null hypothesis. The following data were obtained from a research study comparing three treatment conditions. Treatment 1 Treatment 2 Treatment 3
6 8 10 G=48
5 5 5
1 2 3
0 1 2
T=12S S=26 T=16S S=30 T=20S S=38
a. Assume that the data are from an independent-measures study (like in Chapter 12 normal ANOVA) using three separate samples, each with n=4 participants, and use an independent-measures ANOVA with a=.05 to test for significant differences among the three treatments.
b. Assume that the data are from a repeated-measures study using one sample of n=4 participants and use a repeated-measures ANOVA with a=.05 to test for significant differences among the three treatments.
c. Compare your results from part A and part B.