Multigroup analyses with weighted data PreviousNext
Mplus Discussion > Multilevel Data/Complex Sample >
Message/Author
 tina kretschmer  posted on Thursday, October 01, 2009 - 7:47 am
Dear Linda and Bengt,
This forum is amazing - so much valuable information. I was, however, not successful in finding out how to treat the following problem:

moderation analyses in which the moderator is a 4-level categorical variable,
outcome is continuous,
predictor variables continuous and categorical.
major issue: these data are weighted

I have tried using type=mgroup, estimator mlr with weight=smplwght specified but the data were not weighted as could be seen in the output. I also tried using type=mgroup complex but this requires stratification and cluster, which our data don't have. I know I could try mixture if I categorized the outcome, but I don't really want to do that.

In short, do you have any suggestion as to how to tackle a multigroup comparison of a regression with weighted data?

Thanks a lot in advance,
Tina
 Linda K. Muthen posted on Thursday, October 01, 2009 - 8:01 am
You can use the WEIGHT option with TYPE=GENERAL and the GROUPING option. TYPE=MGROUP is no longer an option. It sounds like you may be using an old version of Mplus.
 tina kretschmer  posted on Thursday, October 01, 2009 - 8:56 am
excellent! this worked! we compared the estimates mplus 4.2 and 5.21 produced and they were slightly different although the exact same syntax was used. can you explain the reason for this?
thanks again,
tina
 Linda K. Muthen posted on Thursday, October 01, 2009 - 9:53 am
The default in Version 4.2 was listwise deletion. The default in Verson 5.21 is TYPE=MISSING. They use different information matrices which could account for the differences. If you look at the summary of the analysis, you will see which information matrix is used in each analysis.
 tina kretschmer  posted on Friday, October 02, 2009 - 12:29 am
that explains a lot of slightly different results i obtained recently with different versions. thanks a lot again, also for making the workshop in berlin recently so much fun!
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: