I just read the paper by Todd Little (A Non-arbitrary Method of Identifying and Scaling Latent Variables in SEM and MACS Models, 2006) and would like to model a curve-of-factors model by using the effects coding method Little and colleagues suggest to scale the latent factors.
So I would like to know what would be the Mplus syntax to constrain each factor's loadings to average one.
You can do this using MODEL CONSTRAINT. Let's say you have labelled two factor loadings in the MODEL command p1 and p2 and you want the average of p1 and p2 to be one. In MODEL CONSTRAINT, you would say and you want the average of p1 and p2 to be one:
MODEL CONSTRAINT: p1 = 2 - p2;
See the user's guide for more details about how to label parameters.
deana desa posted on Thursday, July 28, 2011 - 7:43 pm
Hi Dr. Muthen,
I've question about two indicators identification. My model is as below:
model: g by *item1 item1-item2; numb by *item1 item1-item15; alg by *item11 item11-item22; geom by item24-item25@1; datch by item2(a)@1; item2(e)@0;
I received error such that: THE STANDARD ERRORS OF THE MODEL PARAMETER ESTIMATES COULD NOT BE COMPUTED. THE MODEL MAY NOT BE IDENTIFIED. CHECK YOUR MODEL. PROBLEM INVOLVING PARAMETER 55.
How can I specify the two-indicator factor to be identified?