Hi Sasha--
There is an excellent statistical source on interactions of the sort you
are interested in. It may help you in setting up your tests. The name of
the book is "Interaction Effects in Factorial Analysis of Variance" by
James Jaccard. It should be available at your library, but if not it
only costs about $17. It may appear a bit dense at first, but it should
make sense if you work through the examples.
Anthony
Doug Greve wrote:
Still valid.
Sasha Wolosin wrote:
Is running a t-test contrast still valid if I don't have equal numbers
in the four groups (Male Treatment, Male Control, Female Treatment,
Female Control) or should I be running an F test instead?
Sasha
Doug Greve <[EMAIL PROTECTED]> 4/14/2006 3:18 pm >>>
Yes, you just need to come up with the the contrast matrix taht tests
what you want to test. If the contrast matrix has one row, then it's a
t-test. If there are more than one, then it's an F test. You example is
actually a t-test, I think, just:
(MaleTreatment-MaleControl) - (FemaleTreatment-FemaleControl)
for a contrast of: +1 -1 -1 +1
doug
Sasha Wolosin wrote:
Dear FreeSurfers,
I am interested in examining interaction effects between two sets
of
classes where each covers all the data, let's say Male/Female and
Treatment/Control. I know mri_glmfit can be used to run t-test
comparisons between groups (e.g. All Treatment vs. All Control , or
Male
& Control vs. Male & Treatment), but can mri_glmfit be used to
examine
interaction effects between these two sets of classes (for surface
data)?
my FSGD file looks like this:
GroupDescriptorFile 1
Class MaleTreatment
Class MaleControl
Class FemaleTreatment
Class FemaleControl
Input subjid1a MaleTreatment
Input subjid1b FemaleTreatment
Input subjid2a FemaleControl
Input subjid2b MaleControl
etc...
Thanks,
Sasha
Sasha Wolosin
Research Assistant
Developmental Cognitive Neurology
Kennedy Krieger Institute
707 N. Broadway
Baltimore, MD 21205
ph: (443) 923-9270
[EMAIL PROTECTED]
Disclaimer:
The materials in this e-mail are private and may contain Protected
Health Information. Please note that e-mail is not necessarily
confidential or secure. Your use of e-mail constitutes your
acknowledgment of these confidentiality and security limitations. If you
are not the intended recipient, be advised that any unauthorized use,
disclosure, copying, distribution, or the taking of any action in
reliance on the contents of this information is strictly prohibited. If
you have received this e-mail in error, please immediately notify the
sender via telephone or return e-mail.
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
--
Douglas N. Greve, Ph.D.
MGH-NMR Center
[EMAIL PROTECTED]
Phone Number: 617-724-2358
Fax: 617-726-7422
In order to help us help you, please follow the steps in:
surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
------------------------------------------------------------------------
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
--
Anthony Steven Dick, Ph.D.
Post-Doctoral Fellow
Human Neuroscience Laboratory
Biological Sciences Division
University of Chicago
5841 S. Maryland Ave. MC-2030
Chicago, IL 60637
Phone: (773)-834-7770
Email: [EMAIL PROTECTED]
Alternate email: [EMAIL PROTECTED]
Please visit my homepage at http://home.uchicago.edu/~adick/
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
