I am trying to run a post-hoc power analysis on a previously published report. The intent is to calculate the average obtained power for (the equivalent of) Cohen's effects of d = .20, .50, .80) for all main effects and contrasts.
The study design is as follows: N = 240, repeated measures mixed (split-plot) 2x4(x4) ANOVA. To simplify, the first two factors are between-subjects. Factor A (gender) has 2 levels (male, female obviously), Factor B (ethnicity) has 4 levels totalling 8 experimental groups. Groups are balanced with n = 30 at the smallest unit of observation. Each of the 8 groups performs the same task under 4 different conditions. No information about the degree to which the responses are correlated is given. Pretty straightforward. Hopefully I haven't left anything out.
I can use STATA, GPower, or other online sources to calculate power for one and two way repeated measures ANOVA, but I haven't found a way to do this particular design.
Has anyone had any luck configuring either R, STATA syntax, or done some other voodoo to calculate power for this design?