Re: AMOS:Modeling correlations between observed variables

Posted by David Marso on Mar 24, 2011; 2:54pm
URL: http://spssx-discussion.165.s1.nabble.com/AMOS-Modeling-correlations-between-observed-variables-tp4262072p4262467.html

Hi Tanya,
  I haven't used Amos in a LONG TIME, but was using LISREL in the early 80's and Amos while I worked at SPSS.  Don't have any SEM package available at the moment.  One trick is to simply reparameterize the model so that you create a 1:1 relationship between the observed variables and the latents.
i.e Constrain error variances to 0.
Constrain the Factor loadings from Observed to Latents to Identity Matrix.
Model the Covariance structure of the Latent variables which is actually in this case equivalent to the observed.
Set up the same relation for the Y side and all the time based paths can be set up in the Gamma and Beta matrices.
X=I*Ksi + 0
Y=I*Eta + 0
Eta = Gamma*Ksi + Beta*Eta + resid.

HTH, David