Help on making a 3-way mixed ANOVA

[Jason Levitt]

Hi all!

I have a design with a N of 97 (55 people in one group and 42 in the other). I am interested in the effects of an intervention vs. an active control on reducing a measure of anxiety at 4 time points (baseline, post-test, 1 week follow-up, 2 week follow-up). Now, when I run two 2X2 Mixed ANOVAs with the following code:

anova anxiety intervention / id|intervention time intervention#time if group==1, repeated(time)

anova anxiety intervention / id|intervention time intervention#time if group==2, repeated(time)

I found significant main effects for time for both groups, and a significant interaction between intervention by time for one group but not the other. However, I can't seem to figure out how to make a code to fit them all together and do a 2 (group) X 2 (intervention) x 4 (time) mixed ANOVA. I would greatly appreciate any feedback.

Thanks in advance for the help :-)

[Joseph Coveney]

Here, try this:

anova anxiety group intervention group#intervention / id|group#intervention ///
    time group#time intervention#time group#intervention#time, repeated(time)

Why don't you use mixed?

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endÿofÿdo-file


.

[Jason Levitt]

Yes, I think Mixed is a better approach for this. This is great, thank you!