I am trouble with power analysis. I have a 2 * 3 within factor design and want to used the repeated-measure ANOVA to analyze the data. How can I calculate the sample size？
Usually I used Gpower but I am not sure I do it in a right way. If I want to find the minimal subject numbers to detect the interaction, with the power of 0.9 and middle effect size, I will put the parameter as below：
I am most unsure about the number of measurements, I put 5 because (2*3-1).
And I choose repeated-measure, within factor is right? Or do you have any other software or web can do the power analysis. I am very thankful if you can answer my question or provide me something related to read.