How do I do a power analysis

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How do I do a power analysis
Message posted by Christopher on July 24, 2000 at 12:00 AM (ET)

Please help. I need guidance on how I can conduct a power analysis. I'm doing a project for school in which I have two indepenent variables (score of 1-100 on Personality Trait #1 and score of 1-100 on Personality Trait #2)and one depedent variable (emotion intensity on a scale of 1-25). I will be doing a hierarchiacal multiple regression to evaluate the effects of the two traits and their interaction term on intensity. I need to predict how many subjects I need to test in the experiment so that there is an .80 probability of rejecting the null hypothesis for a medium to large effect size. Can anyone help??

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Re: How do I do a power analysis
Message posted by Denise Jepsen on July 25, 2000 at 12:00 AM (ET)

Sure can help! Try G*Power search on the web for a free download of a fabulous program with all the power analysis you want. Let me know if you can't find it.

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