Random effect in the GMM model PreviousNext
Mplus Discussion > Latent Variable Mixture Modeling >
Message/Author
 Yuchun Peng posted on Wednesday, October 14, 2009 - 8:45 am
Dear Mplus support team,
I have a general issue concerned about the random effect in the GMM model.
Should the random effect for slope factor (given the fact it is significant factor in the Growth model) be added during the stepwise process of deciding the optimal number of clusters.
In other words, 2-Cluster with Intercept random effect->2-Cluster with Intercept and slope random effect->3-Cluster with intercept random effect->3-Cluster with intercept and slope random effect...

Or
The decision on the number of cluster can be based on the GMM model with random intercept factor first. And then add the slope factor afterward to see whether it can improve the model or not
I.E.: 2-Cluster with intercept random effect->3-Cluster with intercept random effect->4-Cluster with intercept random effect (saying the 4-cluster with intercept random model was optimal).. and then run 4-cluster with intercept and slope random effect

The reason why I am asking this is the computation time of adding the random effect for slope factor is very heavy (it takes more than one week for my data!!) I wonder whether it is technically appropriate to only include the slope random effect after the decision on the number of clusters was made.

Many thanks for your classification in advance

With regards
Vicky
 Linda K. Muthen posted on Wednesday, October 14, 2009 - 4:04 pm
If the effects are random, you should allow that when determining the number of classes.
 Yuchun Peng posted on Wednesday, October 14, 2009 - 6:21 pm
Thanks for the answers!!

My question now is is there any way I can speed up the computation time?
I have used the PROCESS option, however, given that the total sample size is over 20,000 and the outcome variable is a categorical variable. It has been running since a week ago. Is it normal?


with regards,
Vicky
 Amir Sariaslan posted on Wednesday, October 14, 2009 - 6:41 pm
Vicky,

Convergence problems and issues relating to computational speed is discussed in the UG, see pp. 384-387.

Sincerely,
Amir
Back to top
Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: