I have data with two factors TREATMENT and TIME both with two levels and a dependent variable RATIO. Besides random intercept for subjects, I want to specify random slopes for both of the independent variables for the mixed effect model in R using lmer.
Currently I have the model
lmer(RATIO ~ TREATMENT + TIME + (1 + TREATMENT + TIME | SUBJECT), data=my.data)
and the following questions.
- Is the above model syntactically correct for specifying different random slopes for treatment and time?
- What could be the reason that the model does not converge, i.e. it gives the following warning?
Thanks in advance