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Thank you very much Anderson! :D Best Regards, Walid > On 2016/07/31, at 16:31, Anderson M. Winkler <[log in to unmask]> wrote: > > Hi Walid, > > Please, see below: > > >> On 31 July 2016 at 06:10, Walid Y. <[log in to unmask]> wrote: >> Hello FSL experts, >> >> I am trying to create a design where i want to check the difference between 2 groups patient and control (TBSS/Glm). >> However i want 1 EV to be a covariate of no interest and two of interest. >> >> Currently Ifm at: >> >> EVs: >> >> G1 G2 Age Variable1 Variable2 >> 1 0 demeand demeand demeand >> 0 1 demeand demeand demeand >> >> Contrasts: >> C1 1 -1 0 0 0 >> C2 -1 1 0 0 0 >> C3 0 0 0 1 0 >> C4 0 0 0 0 1 >> C5 0 0 0 0.5 0.5 > > Contrasts C1-C4 are fine, and the interpretation as indicated below is correct. C5 can only be used if the measurement units of variables 1 and 2 are the same and their sum is meaningful. I am not sure what is your hypothesis for C5 but perhaps an F-test with C3 and C4 (for any effect) or a conjunction (for an effect in both) could be better/more informative. > >> >> I want to test the difference between groups 1 and group 2 taking age as a nuisance covariate and variable 1 and variable 2 covariates of interest. >> >> C3 is the effect of V1 between groups 1 & 2 (taking age and V2 as nuisance covariates) >> C4 is the effect of V2 between groups 1 & 2 (taking age and V1 as nuisance covariates) >> C5 is the effect of both V1 and V2 between groups 1 & 2 taking age as nuisance covariate. >> >> >> Incase i want to check the effect of V1 with age as a nuisance covariance ONLY, then i will remove V2 from EVs and run it as: >> >> >> G1 G2 Age Variable1 >> 1 0 demeand demeand >> 0 1 demeand demeand >> >> Contrasts: >> C1 1 -1 0 0 >> C2 -1 1 0 0 >> C3 0 0 0 1 <= V1 with age as a nuisance covariance ONLY > > This is fine. > > All the best, > > Anderson > > >> >> >> Is my design correct? Thank you for your advice. >> >> Best regards, >> >> >> >> Walid >