Hello everybody!
I just need a small precision for statistical analysis. I would like to compare
the slope of regression between two groups. Therefore I made my fsgdf like
that:
GroupDescriptorFile 1
Title Thickness comparison
Class Control
CLASS Patient
Variable Age
Input subj1 Control 10
Input subj2 Control 15
Input subj3 Control 20
Input subj4 Patient 10
Input subj5 Patient 15
Input subj6 Patient 20
....
And the estimation step with DODS resulted in a design matrix with 4 columns.
How do I have to compute the contrast to answer the following question: do
cortical thickness decrease more steeply with age in the patient than in the
control group? It should be something like 0 0 1 -1 ?
(and 1 -1 0 0 will answer to the question: is there any group difference in
thickness with age being regressed out?).
Thank you very much for your help!
Marie Schaer
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