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 Ting posted on Monday, July 16, 2012 - 8:58 am
Dear Dr. Muthen,

I understand that it is not meaningful to consider the model fit of a just-identified model (say, a path model), because the df is zero. But I haven't read a lot of discussion about the coefficients of just-identified models.
1) Can the path coefficients of this just-identified model be trusted?
2) Is achieving over-identification the top priority, i.e.,if this just-identified path model is what I am interested in, should I sacrifice some parameters(e.g., constrain some path coefficients to be equal or set a nonsig. one to be zero), in order to obtain an over-identified model?

Thanks!
 Linda K. Muthen posted on Tuesday, July 17, 2012 - 11:02 am
1. Yes.
2. The left-out paths should be based on the theory you are testing.
 K Wilkins posted on Sunday, January 27, 2013 - 3:44 pm
Hi Dr. Muthen,

I had a related question. I know that model fit indices such as chi-square are not calculated when analyzing a just-identified model. It seems AIC and BIC are calculated when I run my model, I was curious if I am able to report these?

Thanks!!
 Linda K. Muthen posted on Monday, January 28, 2013 - 10:28 am
AIC and BIC are not absolute fit statistics. They are used to compare models. I can't see that they would be useful to report for a single model.
 Orpha de Lenne  posted on Monday, September 17, 2018 - 5:43 am
Dear Dr. Muthen,

I am trying to test a measurement model. The model is just-identified and as such I do not get model fit statistics. Is there another way to still test the fit of this factorial model?

Thank you.
 Bengt O. Muthen posted on Monday, September 17, 2018 - 2:16 pm
Perhaps you have one factor with only 3 indicators. Then there is no test of fit. If that's not the case, please send output to Support along with your license number.
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