Originally Posted by

**breepi** Hi, I'd really like some help on the following issue - I've been searching the internet for over two hours now, so I'm either completely oblivious to something really obvious, or maybe I'm looking for the wrong thing?

I'm completing an assignment for my research design class, and I'm being asked to find the appropriate number of participants for a study, given an effect size of one, if I wanted to have a power of .95 in a between-subjects experiment

I know the purpose of this question is to get me to recognize the trends between effect size and number of participants, but I can't find a formula anywhere!

Thanks so much for your help!