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!
Variances of categorical variables are not parameters in the model. See the following paper which would deal with this:
Raykov, T., Dimitrov, D.M. & Asparouhov, T. (2009). Evaluation of scale reliability with binary measures using latent variable modeling. Forthcoming in Structural Equation Modeling.
Yoosun Chu posted on Monday, October 02, 2017 - 5:37 pm
Hello, I am running two-level sem. My dv items are continuous, but in the within level, I have some covariates (gender, education, etc), that are categorical. I treated them as exogenous variables. I have an error message: variances for categorical outcomes are not allowed on the within level. Can mplus handle this? I read the above conversation, but it is still not clear for me. Thanks.
You should not refer to variances for categorical outcomes because they are not free parameters to be estimated. But the question is why you have categ vbles as DVs. Perhaps you are incorrectly referring to your IVs as categorical. If this doesn't help - send output to Support along with your license number.