The models specified on within and between should be guided by your research questions and hypotheses.
(1) Yes. (2) Yes. Example 9.2 shows a random slope model. (3) There are no equalities in your model. Structural parameters are not held equal across groups as the default.
I would not use MUML. I would use the default estimator.
patelrj posted on Thursday, August 11, 2011 - 3:14 am
Dear dr. Muthen,
thank you very much for your clear reply. I've added equality constraints to my model, and found all hypothetical links homogeneous between groups, except for one; but the scale used there is very unreliable, so I'm inclined to point to power problems before I theorize a lot about it.
Due to very unequal cluster sizes (unequal classroom composition) I used MUML to handle that type of data. Is it ok to use it in this instance?
1. Is this way correct even though my moderator is dichotomous (boys/girls)? The interpretation would be then, the more someone is a girl, the more predictor affects the outcome...?
2. For the moderation to take place, the interaction term has to be significant. But what about the model fit? Can I compare the fit of a model with freely estimated path from the interaction term to the outcome with a model where this path is constrained to zero?
1. If gender=1 for girl and 0 for boy then the intercept Y is interpreted as the intercept for group boy, while the intercept for group girl would be [Y] + Y on gender. Similarly, Y on X is the coefficient for boy and the coefficient for girl is Y on X + Y on interaction.
2. Yes. Such a test would be equivalent to testing equality of the regression coefficient Y on X between the two groups.