Bayesian RM ANOVA - Does a model with interaction only make sense?
I conducted two independent samples Bayesian ttests to test for a group difference before and after an experimental session:
I also did a dependent samples Bayesian ttest to see if there is a change within groups:
To check for an interaction, I conducted an ANOVA:
As you can see, clear support against the model with 2 main effects and interaction. However, if I have a model with interaction only, the BF is BF = 0.55, rather inconclusive.
Now my question: How much does a model with interaction term only make sense? I recall reading that a model should always include the main factors as well, but I do not remember the source. Can it be justified that I only have the interaction effect in the model? It sounds like cherry picking to me.