I'm using a linear mixed effects model to analyze the reaction time of learners of English as a Second Language (ESL). I have two factor variables: grammaticality (grammatical v.s. ungrammatical) and finiteness (finite v.s. nonfinite), as well as one numeric variable: proficiency.
I'd like to analyze how their proficiency may affect their sensitivity to grammaticality and finiteness, so I built the model like this:
fitnonnative7 <- lmer(data = nonnative, formula = RT ~ Grammaticality * Finiteness * Proficiency + (Grammaticality|subject) + (Grammaticality|item))
I got a marginal interaction between grammaticality and finiteness as well as a a marginal interaction between grammaticality, finiteness, and proficiency. How am I supposed to do the post-hoc analysis?
The result of the linear mixed effect model can be found here. I also tried the
marginaleffects package to estimate the three-way interaction. Details of this package can be found here. This is what I have have so far:
I might have done something wrong, as the result doesn't tell me the interaction between grammaticality and finiteness. How do I analyze the two-way and three-way interactions properly?