[R-sig-ME] Random slopes for categorical variables

Timothy MacKenzie |@w|@wt @end|ng |rom gm@||@com
Wed Oct 6 05:20:00 CEST 2021

Hello All,

I had a basic question. For continuous variables (X) killing the
intercept in the random part kills the correlation between random
effects (intercepts and slopes):

(0 + X | ID)

But for categorical variables (CAT) killing the intercept actually
allows for all levels of CAT (including the reference level) to be
correlated that is:

(0 + CAT | ID) estimates more correlations than (CAT | ID)

Am I correct?

Tim M

More information about the R-sig-mixed-models mailing list