I am working on a 2x2 repeated measures ANOVA and I am having trouble finding much information about it. Basically I taught the same group of 25 children words using 4 different flashcard methods that varied by the number of times they saw each word (high vs low) and the percentage of words included that were new (high vs. low).

I figured out the analysis ok using repeated measures on SPSS, but I am not sure about the assumptions I need to consider. Specifically, do I need to discuss compound symmetry/sphericity? At first I didn't think so because there are only 2 levels of each factor. However, overall there are four groups, so compound symmetry may play a role. So, stats people out there what do you think??

Thanks very much for any help you can offer.