I have made an experiment with 28 subjects. All made the experiments under 3 different conditions (A, B and C). So I have a table like this:
No. A B C 1 3 6 4 2 6 2 6 ...
Now I just want to perform a RM-ANOVA or a Friedman test or a Quade test. That's not the problem.
I want to use GPower to determine the necessary alpha value to detect e. g. a "medium" effect. I do not get how to use GPower in this case.
Here is a screenshot of how I do it for a t-test:
Now I want to do the same for more than 2 conditions. Can somebody point out how to do that? Here's a screenshot of the possibilities:
EDIT: I looked it up, and apparently it is called One-way repeated measures ANOVA. So how can I to One-way repeated measures ANOVA with G*Power to determine the required alpha value (given effect size and so on)?