According to Kirk's (1995) Experimental design: Procedures for the behavioral sciences, "Scheffš's procedure is always congruent with the omnibus F test. If the omnibus F test is significant, there is at least one contrast among the means that is significant according to Scheffšs test, and vice versa." (p. 155) Michael T. Scoles, Ph.D. Associate Professor of Psychology & Counseling University of Central Arkansas Conway, AR 72035 501-450-5418
>>> David Epstein <[EMAIL PROTECTED]> 4/3/2007 2:43 PM >>> On Tue, 3 Apr 2007, Rick Froman went: > How would you interpret an ANOVA result where the F-test was > significant but none of the multiple comparisons were significant in > an HSD comparison? Initially, I wrote a response as follows: "Off the top of my head, I would say: An overall effect was detected, but the sample sizes within individual cells were not sufficiently large to attribute the effect to any specific pairwise comparison. "Then I would talk, with due caution, about what it LOOKED like." Then I did a Google search and found an explanation that's more abstruse, but still seems to invoke the problem of small sample sizes: <http://www.ats.ucla.edu/STAT/spss/library/manglm.htm> (scroll down to the section "My tests don't agree!"). Note that the explanation does *not* seem to be that you're missing "some more complicated contrast among the means." --David Epstein [EMAIL PROTECTED] --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english
