Hi,
I am running a study on 8 subjects. Before testing all 8 subjects were assumed to be drawn from the same population. However, subjects 1-6 and subjects 7-8 show very different results in my data. I also have reason to believe that there is a small theoretical possibility that they are from different populations. I have therefore run my analysis (friedman’s ANOVA) in three ways; (1) on all subjects, (2) on subjects 1-6, and (3) on subjects 7-8.
Since the last two statistical tests are post-hoc, do I need to adjust the p-value accordingly? If so, how do I do this?