Just to clarify, you can do this analysis in FS, but not in QDEC. You'll have to create an FSGD file. Do a search for FSGD on our wiki to get examples that you can generalize from. doug
MCLAREN, Donald wrote: > Charlotte, > > There is no difference, from a statistical perspective, of nuisance > factors and covariates. > > The key questions are: > (1) Do any of these covariates have a differential effect on thickness > between groups? > (2) Do you want to compare the actual group means or the > covariate-adjusted group means (e.g. test the means for subjects as if > the subjects all had the same covariate values)? > (3) Do you have enough subjects to add 5 covariates? > (4) Do you have a valid reason for why all the covariates would have > an effect on thickness? One can always add more covariates to reduce > the error, but its not always a good thing to add covariates just to > reduce the error of the model. > > On 2/23/12, Charlotte Bernard <chak...@live.fr> wrote: > >> Dear Freesurfur users, >> >> I have a question about the design for a surface based analysis! I want to >> compare controls and patients. I have 5 covariates. One is a continous >> variable. The others are categorial variables (4 with 2 levels and 1 with 5 >> levels). I want to ajust my result with all of thoses variables. I am >> interested in the difference in thickness between patients and controls. >> Is it possible to construct such design? >> Can I put some of my variables in the "nuisance factors" ? I don't really >> understand the difference between "nuisance factor" and covariabes. >> I really hope somebody can help me. >> Thanks for all! >> All the best, >> Charlotte >> >> > > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
