Question

Give an example of an experiment when a repeated measures ANOVA would be appropriate.

and

What is the purpose of using an ANCOVA instead of an ANOVA?

Answer 1

An example where repeated measure ANOVA is appropriate is when you want to investigate an effect of exercise training program on blood pressure and want to measure blood pressure at three separate time point. It is like usual ANOVA but the difference is the a repeated measure ANOVA do comparison between related group and not independent group like normal ANOVA.

2. The purpose of ANCOVA instead of ANOVA: ANCOVA which is known as Analysis of covariance is used to test the main and interaction effects of categorical variables on a continuous dependent variable, controlling for the effects of selected other continuous variables, which co-vary with the dependent. The control variables are called the "covariates."