# Using G*Power to calculate sample size for Mixed ANOVA

I'm trying to calculate the sample size for a 2x2 Mixed ANOVA using G*Power 3.1.9.2 I have entered the following values in F tests ANOVA: repeated measures, between factors - A priori: Effect size = 0.5, alpha error = 0.05, Power = 0.95, No. of groups = 2, No. of measurements = 2, Corr = 0.5

The total sample size was 42. However, I'm conducting an experiment where participants will do two different IVs and two Mixed ANOVAs analysis will be done. e.g. between IV1 (with 2 levels) and within IV1 and between IV2 (with 2 levels) and within IV1

Hence, should my total sample size be 84?

Any help would be much appreciated Thanks

• I think you have some things mixed up. – Michael Chernick Mar 28 '17 at 21:29
• I can't believe g*power still exists. I used that thing several decades ago – HEITZ Mar 28 '17 at 22:04
• @MichaelChernick I would greatly appreciate it if you could let me know what I have got wrong here. I am conducting an experiment where all participants do between IV1 and between IV2 along with the within IV (so 3 IVs in total). Between IV1 and between IV2 each have two levels. (The between IVs are happiness and mood scales, so participants can only be split into high/low after they complete both the scales) So a Mixed ANOVA analysis will be done with between IV1 and within IV and another Mixed ANOVA analysis will be done with between IV2 and the within IV. – Charlie Mar 28 '17 at 22:11
• @HEITZ I'm more than happy to try another software or tool for calculating the sample size in my case. – Charlie Mar 28 '17 at 22:14