Need help determining sample size please

[gardagh]

Hi all,

I could really do with some help. A caveat is that I am a compete statistics newbie.
I have a questionnaire with 20 questions. I have 7 variables that these questions are indicators for. The variable with the most indicators has 4 indicators. The rest are 3 or 2. My research (hypthoses) is comparing the effect of one variable on the other 6.

I am struggling to get survey responses so am hoping to hit the minimum number required for analysis. A level of power equal to .80 would suffice.

I have attached some pictures from Smart pls but please let me know what other info you need.

any and all help gratefully accepted.

Thanks,

George.

[jmbecker]

First, I would recommend using the G*Power Tool.
Second, I would recommend reading this forum thread: viewtopic.php?f=5&t=4009
Third, you may have a problem in determining your effect size as you have only one predictor for several depenent variables. Thus, using the estimated f² effect sizes from your current model does not help you as they are somewhat misleading (f² is the additional explained variance relative to the unexplained variance of the predictor; if you have only one predictor it is quite a strong effect as you compare against zero explanaition).
I would actually use a weak effect size to determine the minimum sample size (e.g., 0.02 ≤ f² < 0.15) in allmost every study to get a conservative estimate of the required sample size.