How to fit two random effects separately in lme?

Question

I\'m doing Linear mixed-effects model fit by REML in nlme package. And these are codes that work for me:

# Linear mixed-effects model fit by REML (intercept and          


        

Answer 1

I think it is possible to include two random effects seperately (one for speaker and one for time) using lme() by the following code:

x4 <- lme (DV ~ IV1 + IV2 + IV1*IV2, data=a.frame, random=~ speaker + item -1 | id),

with id a higher level variable in which both speaker and item are nested. If you don't have such a variable, you could introduce it as a new variable with value 1 for all observations.