Re: AMOS ERROR MEASSAGE

Posted by David Marso on Aug 04, 2011; 9:10pm
URL: http://spssx-discussion.165.s1.nabble.com/AMOS-ERROR-MEASSAGE-tp4667749p4667959.html

You really need to be more specific about the model you are attempting to fit.
Is it a simple factor model?  
A more general SEM model?  
How many variables?  
How many cases?
What equations are being estimated?  
How many free parameters?  
What parameters are already constrained?  
What is the covariance structure of the latent variables?

"The sample moment is not positive definite....."
Perhaps quote the 'reasons which you fail to understand'.  
Someone here WILL understand.
Are any variables linear combinations of others (that is the most basic reason)?
Can you post the path diagram somewhere so we can see it?
Can you post the covariance matrix?
---
These are fundamental questions which we need to know the answers in order to help!!!
If any of this is Greek to you then you may want to review the theoretical foundations of SEM, Factor analysis and regression analysis so we are using an agreed upon vocabulary.
HTH, David

rks wrote

I am trying to test my model and I keep on getting this message "The model is probably unidentified. In order to achieve identifiability, it will probably be necessary to impose 1 additional constraint." when I view the text output.Also I get "An error occurred while attempting to fit the model.The sample moment is not positive definite.It could fail to be positive definite for any of the following reasons..."then it give couple of reasons which I fail to understand.
Please someone help.