Ah, hello Volkmar,
You managed to send this during the (long) time that it took me to
write my waffley reply to Nick!
> If you want to test differences between your two
> groups, you will have to weight the subject factors as you would do for
> each group main effect. For 2 groups with size N1 and N2 this would look
> like
>
> 1/N1*ones(1,N1) -1/N2*ones(1,N2) 1 0 -1 0
That's similar to what I'd guessed, except that I'd also "averaged"
over the other factor, to give
1/N1*ones(1,N1) -1/N2*ones(1,N2) 1/2 1/2 -1/2 -1/2
which of these do you think makes more sense? I hesitate to argue, but
mine seems slightly more like the [1 1 -1 -1] that I think Nick was
expecting...
And do you have a good reference for this? I've mainly been trying to
work it out as I go along ;-)
All the best,
Ged.
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