Anonymous posted on Thursday, May 19, 2005 - 10:35 pm
All of the variables in the model are dichotomous and the model is being run using the theta parameterization.
I have two questions concerning the models below. First, the models are nested, however, when running the models, the number of df given when using the difftest option is not equal to the difference between df in the H0 and H1 models. In the model with the Dep and Anx latent factors, there are 30 df, and in the model with the CF latent factor, there are 27 df; yet in the difftest there are 5 df.
Second, does the program account for the covariance between z1-z4, or does that need to be specified. If that does need to be specified, being that z1-z4 are dichotomous variables, is the covariation between these factors done by: q1 BY z1* z2 (c); q2 BY z1* z3 (d); etc. for all pairs.
I suspect that you are using the WLSMV estimator. The degrees of freedom for WLSMV are not computed in the regular way. See formula 110 in the Technical Appendices which are on the website. This is why you don't see an agreement in the difference between the two degrees of freedom.
Yes, the program does account for the covariances among z1-z4. You should not include them in the model. The CATEGORICAL option is only for dependent variables so z1-z4 should not be specified as categorical.
Anonymous posted on Friday, May 20, 2005 - 2:11 pm