When reporting a two way 2 x 3 mixed ANOVA I have recently heard that the interaction effect should only be reported if the two main effects are significant (APA style). Is this correct?
Solved – Reporting main effects and interaction from ANOVA
anovainteractionreporting
Best Answer
If you report the interaction, you need to report the main effects as well, whether pooled (as @Frank suggests) or "plain". I usually report some predicted values as well - often in a graph - as I think these show things intuitively.
I agree with @Frank about significance tests. That's not a good way to build a model.
I think you may have mis-remembered the advice. It is true that you should not interpret main effects in the usual way when there is an interaction. And I've heard some people say that you should not report an interaction if it is not significant, although I don't agree.