1. Is it possible to restrict only slope to have latent class structure? 2. based on the above example code, is latent class capturing the heterogeneity of random intercepts and slopes (i.e. after controlling for the 'effect' of x on both mean intercept and slope)?
I am thinking of a random intercepts and slopes model (for longitudinal data), but would like to have random slopes follow a mixture normal (latent class), while keep random intercept a regular normal. Can growth mixture model be applied in this situation?
I think you can achieve what you want by holding the mean of i equal across classes, for example,
in the overall part of the MODEL command.
Lei Yu posted on Thursday, April 10, 2014 - 7:17 pm
Thanks, Dr Muthen
That really helped. I do have a follow-up question,
I tried to get the Lo-Mendell-Rubin test and the bootstrapped likelihood test using TECH11 and TECH14. But Mplus shows the warning message that neither was available for the model with type=mixture random.
Is there a statistic to determine the optimal number of classes for longitudinal data other than AIC or BIC?
My sample code
Data: file is 'mplusdta.dat'; Variable: names are x y1-y18 t1-t18; usevar =x y1-y18 t1-t18; TSCORES = t1-t18; class = c(2); missing = ALL(-1234); Analysis: type = mixture random; processor=4; STARTS = 100 8; Model: %OVERALL% i s | y1-y18 at t1-t18; i s on x;