Dear knowledgeable tipsters: Sorry for the cross posting to tips and Psychteach; please delete if you have already seen this question in the other list.
I have some SPSS questions: Please answer me off list. First of all, I am running a mixed ANOVA with one repeated measures variable with 5 levels and one between measures variables with 2 levels. I wanted to run planned comparisons but SPSS 12 won’t let me. It tells me that I need at least 3 groups and that I don’t have three groups. Can someone explain this to me and tell how to run my analysis? Second, SPSS has several (about 12) different planned comparisons I can run. I know that some are more conservative and some less conservative, but how does one decide between so very many which ones to run? Third, for planned comparisons, can’t I just run t-tests for the comparisons of interest, rank order them from highest to lowest and divide each obtained p-value by alpha divided by the number of total comparisons for the lowest p-value, alpha divided by n-1 total comparisons for the next and so on, until I reach the point of non-significant comparison of alpha? If I do that, then how do I get effect size analyses? Effect size analyses in SPSS seem to be tied to post-hoc comparisons. Is it sufficient to say that my confidence intervals don't overlap? Well, one more finally, why in the world would I want to do an omnibus post-hoc when I have a hypothesis driving planned comparisons and how does all this work out in SPSS? YUCK! Why can stats be what they were 30 years ago when I was in grad school? Annette Annette Kujawski Taylor, Ph.D. Professor of Psychology University of San Diego 5998 Alcala Park San Diego, CA 92110 619-260-4006 [EMAIL PROTECTED] N����!jx ��2��칻 �*m�����!����,�w���[�� v�܂&���r�+)��
