On 27 Oct 2002 06:37:09 -0800, [EMAIL PROTECTED] (Ton de Craen) wrote: > I want to do a power calculation for a repated measures design. I > found a software program on the internet > (http://www.ssicentral.com/other/hlmod.htm). It is free, but is does > not contain any help function. Does anyone how to use this program. > Especially the repeated measures options. It asks for six parameters, > the first three are easy, but I have problems with the last three. > Does anyone know how to do this? I already have contacted the creator > of the program, but I have received no answer.
- what to do - Approximate your design and power calculation with the nearest, likely, paired t-test. Or, look at the contrast of interest, and compute the power based on the simple ANOVA on the contrast; you probably want to dummy up some data for this, if you don't have good pilot data on hand. Having said that, I will say that you should probably not use any power analysis program that does not have ample documentation, including sample problems -- plug in numbers to match previous results, and match (with *some* accuracy) your design. The problem has been asked before, of course. I don't remember being impressed by Repeated Measures reported (even) for expensive programs, though there was a recommendation or two (I think I recall). Good luck. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
