Re: [Freesurfer] Difference between t-test within 3 group ANOVA and separate t-test

2009-10-23 Thread Douglas N Greve
It depends on a couple of things. If you don't have any continuous covariates, then the difference will be in the computation of the noise and the DOF. With all groups, you'll be computing the noise variance across all subjects, and you'll have a much higher DOF. The size of the difference betw

[Freesurfer] Difference between t-test within 3 group ANOVA and separate t-test

2009-10-23 Thread Alex Millner
Hi - Thanks for your help. I have 3 groups and am trying to run an ANOVA and series of t-tests. First, I ran mri_glmfit with two rows in my .mat file (1 -1 0, 1 0 -1) for the ANOVA. Then, before I ran into this webpage https://surfer.nmr.mgh.harvard.edu/fswiki/FsgdExamples, to do a follow up