On 17 Jul 2002 07:42:10 -0700, [EMAIL PROTECTED] (Alfred Barron) wrote: > Hi all, > > I have a client doing a bunch of samll sample > t-tests, about n = 3, 4 sample size/group. > For the moment, I'll skip the power. > > Does anyone know of any studies or simulations > showing how poorly the nominal alpha level > coverage can be ?
"how poorly" under what abnormal conditions? t remains rather well-behaved with equal Ns (especially in contrast with bad behavior for unequal Ns, with unequal variances). Comparisons between long-tailed distributions produce empirically computed "t-test" distributions where the tails are shorter than for t; and conversely, short-tailed distributions produce longer tails. Does that help? -- 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/ . =================================================================
