ooops made a mistake in the last email....
Me again....Two things this time....
1) Can someone tell me why when I did a Wilcoxon Signed Ranks test (non-para) I found signficant differences between a) time 1-time 2 b) time 1-time 3 c) time 2 and time 3
BUT when I did the parametric alternative (repeated measures ANOVA) I got significant differences on a) time 1-time 2 b) time 1-time 3 but c) time 2 and time 3 was not significant....
I thought that as non-para tests are not as sensitive as para tests that it would've been the other way round, that the para test would show something significant that the non-para wouldn't find.....
Any ideas?
2) Given a data set of 155 participants on before, pre- and post- test (time 1, time 2 and time 3) what reason(s) would you choose to do a Friedman and Wilcoxon Signed Ranks instead of the repeated measures ANOVA when all your other tests have been parametric?
Last minute panic before the viva on Friday!!
Helen x
