Appology if it is rather long. But i'm confused! What assumptions do i need in order to answer this question? With having two segments in the population that you wish to compare with respect to their ...
I am new to g*power and have a question about which test I have to choose and how to interpret the given sample size. I have 2 measurements (pre / post), one control-group and one intervention-group. ...
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 ...
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. ...
When estimating the effect size for determining optimal sample size for a statistical test, the textbook approach seems to do this from pilot studies or the like. Is it also legal to define effect ...
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 ...