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I used SPSS to run a two-way within subjects ANOVA (IV1 and IV2). The IV1 * IV2 interaction was not significant but main effects of both IV1 and IV2 were. I would like to know if the trends followed a significant linear or quadratic pattern. Would it be right to look at the Tests of Within-Subjects Contrasts table produced automatically by SPSS? Or would I need to run other tests to look for this?
Also, may I ask how I can make sense of this table?
Thank you so much in advance!
Yes, that table gives you results for the individual contrasts for both main effects and the interaction. There is some evidence of an interaction in the last significance value. You would likely find it helpful to ask for EMMEANS (Estimated Marginal Means) for both main effects and the interaction in order to see how they differ. In this model with just within-subjects factors, these are the same as the observed means. You can estimate any types of contrasts among these you want using the MMATRIX subcommand, which requires using command syntax (which can be edited after pasting it from the dialogs).
