- Thread starter NikYouKnow
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- Tags interaction interpreting graph main effect multiple regression

Assuming you have interaction, If A has greater impact on C than B has on C at some levels of the other predictor , but at other levels of the other predictor B has greater impact on C than A has on C, than the interaction is disordinal (and that is a real pain to interpret). If not the interaction is ordinal.

You always have main effects with interaction (in fact you can't remove main effects even if not significant when you have significant interaction). You just have to interpret the main effect at specific levels of the predictor they are interacting with (which is called simple effects often in the ANOVA literature).

http://analytics.ncsu.edu/sesug/2011/ST07.Lewis.pdf