GMM - variance of slope is fixed to be 0 PreviousNext
Mplus Discussion > Growth Modeling of Longitudinal Data >
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 SF Wang posted on Wednesday, September 25, 2013 - 4:59 pm
Dear Professors,

when doing parallel process GMM, I was faced with warning message about PSI matrix. A random slope is involved. In addition, I noticed that the variance of the random slope is not significant. Therefore, I fixed its variance at 0. This gets rid of the warning messages.

But I am not quite sure about the interpretation of the slope parameter. Does it indicate everyone has the same slope? if so, subjects are categorized to different latent classes solely based on their intercepts? - seems not so since four latent classes identified have quite different mean slopes.

Any advice is appreciated!

The model is:
fi fs fq | F0@-1 F6@0 F12@1 F24@3;
ci cs cq | C0@-1 C6@0 C12@1 C24@3;
cs@0;
cq@0;

Shufang
 Linda K. Muthen posted on Thursday, September 26, 2013 - 4:22 pm
In this case, you have the same slope within class not overall. Slope means can differ.
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