Interpreting "interaction" effects between
continuous variables is a tricky endeavor. See for example:
http://www.nd.edu/~rwilliam/stats2/l55.pdf
http://www.ats.ucla.edu/stat/sas/faq/spplot/reg_int_cont.htm
Or goggle "interaction continuous variables"
cheers,
-MH
On Wed, 2011-10-26 at 12:45 +0100, SUBSCRIBE SPM kay wrote:
> Hi,
>
>
> In 2nd analysis, I want to test interaction of 2 covariates: self-concept and age but I don't know how to do this.
>
> I googled a lot but found only interactions between a categorical factor and covariate..
>
> Is interaction btw 2 covariates possible and it's just me who can't search properly,
>
> or is the interaction unplausible in spm?
>
> And if it's possible, what should be the contrast values?
>
>
> Thanks a lot, I'm looking forward to your answers.
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