Please see in line responses. Sorry for the delay.
On Fri, Nov 2, 2012 at 8:59 AM, Anja Dietrich <[log in to unmask]> wrote:
> Sorry for the empty message. Here is the question:
>
> Dear experts,
>
> since there is no opportunity to compare groups in a flexible factorial design in spm, I set up a mixed design ANOVA in GLM flex (see attachment for the design matrix).
>
> The model consists of 3 factors:
> group (3 levels)
> condition (2 levels)
> the obligatory subject factor
>
> and a group/ condition interaction
>
> Because contrast definition differs from that in SPM, I would be very happy if one can help me to define the contrasts correctly.
>
> First of all I'd like to define a giant f contrast to check if any column of the design matrix differs from 0.
>>>> This doesn't make any sense to do. I presume you want to test if any of your group/conditions are different than 0. Here is how to do it.
Any group different than 0:
I.Cons(x).Groups={columns representing factor 1} [1 2 3]
I.Cons(x).Levs=0;
I.Cons(x).ET=1;
Any condition different than 0:
I.Cons(x).Groups={columns representing factor 2} [4 5]
I.Cons(x).Levs=0;
I.Cons(x).ET=1;
Any group/condition pair different than 0:
I.Cons(x).Groups={columns representing the interaction} [6 7 8 9 10 11]
I.Cons(x).Levs=0;
I.Cons(x).ET=1;
>
> Further I'd like to create F and t contrasts like the following:
> Group1Condition1 / Group2Condition1
did you mean less than?? Group1Condition1 < Group2Condition1
I.Cons(x).Groups={column for G2C1 then G1C1} [8 6]
I.Cons(x).Levs=2;
I.Cons(x).ET=1;
> Group1Condition1 > Group2Condition1
I.Cons(x).Groups={columns for G1C1 then G2C1} [6 8]
I.Cons(x).Levs=2;
I.Cons(x).ET=1;
ET is 1 for both because these are between-subject comparisons.
[ ] indicates what columns should be in the { }.
>
> Thank's a lot in advance!
>
> Anja
>
>
>
Hope this answers your questions.
|