Multiple group analysis for second-or... PreviousNext
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 HALUS posted on Thursday, June 11, 2009 - 2:20 pm
Hi,
As the user guide said, in multiple group analysis, intercepts, thresholds, and factor loadings are held equal across groups as default. But does this also apply to second-order factor model?

I have a second-order factor model: three second-order factors and each second-order factor has two first-order factors (each first-order factor has multiple observed variables).
I have no problem constraining the first-order factor loadings across groups but have difficulty holding the second-order factor loadings equal across groups.
 Linda K. Muthen posted on Thursday, June 11, 2009 - 4:28 pm
These should be held equal as the default. You should not have to do anything to hold them equal. Please send the output and your license number to support@statmodel.com.
 Thomas Eagle posted on Thursday, December 04, 2014 - 9:14 am
I am having trouble fitting a multiple group model with 2 2nd order factors. I can fit the two groups separately just fine with the model structure I have, but when I attempt to fit them using the default multiple group mode setup I get non-convergence and the error is related to the mean of one of the 2nd order factors (183 = alpha of 2nd order factor SpRelInt)

THE STANDARD ERRORS ...
THE MODEL MAY NOT BE IDENTIFIED...
PROBLEM INVOLVING THE FOLLOWING:
Parameter 183, Group NOT_ENGAGED: [SPRELINT]

THE CONDITION NUMBER IS -0.348D-14.

THE ROBUST CHI-SQUARE...

I thought the means of 2nd order factors were held constant across groups. I know I have to free up, or fix some values somewhere. When I tried to fix the mean of SpRelInt to zero the error message remains the same.

Tom
 Bengt O. Muthen posted on Thursday, December 04, 2014 - 11:38 am
Perhaps you don't fix the intercepts of the 1-st order factors to zero in your analysis.
 Thomas Eagle posted on Thursday, December 04, 2014 - 5:33 pm
Bengt,

I figured out what I was doing wrong. When I set the 2nd order factor means/intercepts to zero for BOTH 2nd order factors the model converged nicely. I thought that was done automatically. This way I could leave the 1st order factor intercepts free. My bad. Thank you! You are always so patient and helpful!

Tom
 Bengt O. Muthen posted on Friday, December 05, 2014 - 10:49 am
But for scalar invariance, I think you would want the means of the second-order factors estimated in all but one group so you can compare them. That then requires that the first-order factor intercepts are zero in all groups and the factor indicator intercepts are held equal across all groups.
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