jsnell55 <[EMAIL PROTECTED]> wrote: : My question is this: If I assume that a placebo group (no treatment) : demonstrates improvement in bone growth among 40% of the patients, will I : need a larger sample size to power the study, than if I assume 65% of the : placebo group will demonstrate improvement in bone growth?
example 40% post mean = 10 65% post mean = 20 Treat post mean = 20 There is no effect for the 65% so obviously the bigger the placebo effect, the larger the sample size you need . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
