An author did not report an effect size so I am hoping you might be able to help me calculate it. I know the Means are: Condition 1: 326 Condition 2: 558 Sample size: Cond1: 11 Cond2: 12 T-test p ...
I was able to calculate the sample size using two different effect sizes 0.3 and 0.5 and each gave me different sample sizes. 0.3 gave me 82 and 0.5 gave me 26. I have 45 students in that gradelevel. ...
I need to calculate effect size for a mixed ANOVA design. I need it because I'm using GPower3 to calculate a rough sample size for a full study. I have pilot data. Based on this page: ...
What does it mean for a study to be over-powered? My impression is that it means that your sample sizes are so large that you have the power to detect minuscule effect sizes. These effect sizes are ...