SPSS - planned comparisons

Hi, sorry if this is very elementary, I have been having great difficulties with it!

I have a 2X2X3 repeated measures design, wherein all main effects and interactions are significant. I would like to run planned comparisons on the interaction of on of the factors (with 2 levels) on the factor with 3 levels, but am having great difficulty doing this. I tried doing it via the "contrasts" option within GLM, and changing the comparison for the 3-levelled factor to "repeated", but within the ANOVA output it does not break the 3-level factor down as a function of the 2-level factor it is interacting with.

How do I achieve this? I hope it makes sense, I have searched the net but can't find anything on within subjects planned contrasts, only contrasts with a between-subjects variable!


Hi, thanks yes I had found that on my initial searches. However, for both of his example he has a between subjects factor allowing post hoc comparisons (tukey, bonferroni etc). All of my factors were manipulated within subjects.