AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

History of AFNI updates  

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February 26, 2009 02:25PM
> I take it from your answer that the ANOVA won't work for unequal sample sizes in each group (11 13).

You can run 3dANOVA3 -type 5 because of unequal number of subjects across group.

> main effect of group for each condition

This is a two-sample t-test, and you can write up a script for color condition like

3dttest -prefix ... \
-set1 ColorSubj1inGroup1 ColorSubj2inGroup1 ... \ # 11 subjects
-set2 ColorSubj1inGroup2 ColorSubj2inGroup2 ... # 13 subjects

and do the same for Achromatic condition.

> main effect for each condition

Do you mean the effect of Color condition for all 24 subjects? And the same for Achromatic condition? If so, you need two one-sample t-test:

3dttest -prefix ... \
-base1 0 \
-set2 ColorSubj1 ColorSubj2 ... \ # 24 subjects

3dttest -prefix ... \
-base1 0 \
-set2 AchromaticSubj1 AchromaticSubj2 ... \ # 24 subjects

> any group x condition interactions

Get Color-Achromatic for each subject, then run a two-sample t-test:

3dttest -prefix ... \
-set1 (Color-Achromatic)Subj1inGroup1 (Color-Achromatic)Subj2inGroup1 ... \ # 11 subjects
-set2 (Color-Achromatic)Subj1inGroup2 (Color-Achromatic)Subj2inGroup2 ... # 13 subjects

HTH,
Gang
Subject Author Posted

Anova Unbalanced design

RN March 05, 2007 02:36PM

Re: Anova Unbalanced design

Gang Chen March 05, 2007 04:25PM

Re: Anova Unbalanced design

RN March 06, 2007 02:43PM

Re: Anova Unbalanced design

Jim Bjork March 07, 2007 03:24PM

Re: Anova Unbalanced design

Gang Chen March 08, 2007 04:33PM

Re: Anova Unbalanced design

Jim Bjork March 08, 2007 05:03PM

Re: Anova Unbalanced design

Erik O'Hanlon February 25, 2009 12:42PM

Re: Anova Unbalanced design

Gang Chen February 25, 2009 03:38PM

Re: Anova Unbalanced design

Erik O'Hanlon February 26, 2009 10:16AM

Re: Anova Unbalanced design

Gang Chen February 26, 2009 02:25PM

Unbalanced design

Michale March 17, 2007 08:56AM

Re: Unbalanced design

Gang Chen March 19, 2007 10:43AM

Re: Unbalanced design

xiaochu zhang March 01, 2009 11:01AM

Re: Unbalanced design

Gang Chen March 01, 2009 04:59PM