adel powell posted on Saturday, December 17, 2011 - 4:05 pm
I am trying to generate multilevel categorical data. I am trying to study various aspect of that type of data. I am having problems. My data is ordinal but non-normal. I am getting this error: *** ERROR in MODEL command Variances for categorical outcomes are not allowed on the within level. Variance given for: Y1
Can Mplus not do multilevel modeling on categorical non-continuous data?
I was thinking Mplus can treat the data like Logistical multilevel modeling where the within error is estimated by pie/3. I forgot the exact figure?
Yes, Mplus can do this. But with categorical outcomes there is not a free within-level variance parameter so you can't estimate/mention that in the MODEL command, which is what the error message complains about. As you say, with logit link the residual variance is pi-square/3, that is, a fixed quantity, not a free parameter. Mplus uses that fixed quantity implicitly.
Cecily Na posted on Friday, March 01, 2013 - 8:29 am
Hi Linda and Bengt, I have a categorical outcome (three levels) in a two-level model. The model syntax is as following, (A, B are predictors at the within level, C is the categorical outcome, and D is the predictor at the between level). Is the following syntax correct? Why is the model syntax for categorical outcomes the same as for continuous outcomes?
%Within% C ON A B; %Between% C ON D;
In a multilevel model for continuous outcome, the intercept or slope of the within level outcome is modeled as random and treated as a latent factor at the between level. For categorical outcome, what is modeled as random? Thanks a lot!