I have a question about the interpretation of the results of a multi-membership LMM computed with the brm function. One of my predictors has several levels but in only some of these levels the 95% credible interval crosses zero while for the other it doesn’t. What does that mean for the overall effect of this predictor?
To give an example: I have dyadic data. The response is a similarity measure between two individuals. My predictor is rank. So I want to see if two dominant individuals are more similar to each other than a dominant and a subordinate individual or two subordinate individuals.
Here is the function we used:
mRank.brm<-brm((Gunif)~ DomDyad+z.Years +SeasonSame+
(1 + SeasonSame.dry17+SeasonSame.wet17 +SeasonSame.wet16||GroupDyad)+
(1 + SeasonSame.dry17+SeasonSame.wet17 +SeasonSame.wet16||mm(ID1, ID2)),
data=test.data, backend=“cmdstanr”, control=list(adapt_delta=0.999, max_treedepth=20))
Here ist the output:
For the predictor DomDyad, only the level OthOth seems to have an effect. How would I describe this result now?
I hope someone can help me out.