I would like to do a chi-square difference test for MLMV estsimation. The instructions for doing so are clearly laid out in the Mplus manual. When I attempt to do so, however, I get the following error message:
*** WARNING in Savedata command DIFFTEST is valid only for estimator WLSMV. Request for DIFFTEST will be ignored.
Any ideas as to why?
Also, I apologize if this is a silly question, but I was wondering if it is possible to perform CFA analyses with single indicators using Mplus? I know you can do it in AMOS by plugging the reliability value of the measure into the error term of the indicator.
Thanks again for your excellent advice and suggestions.
Anonymous posted on Tuesday, September 13, 2005 - 2:37 pm
I am running a CFA with 8 categorical variables, 1 factor.
here are the results: TESTS OF MODEL FIT
Chi-Square Test of Model Fit
Value 120.295* Degrees of Freedom 17** P-Value 0.0000
* The chi-square value for MLM, MLMV, MLR, WLSM and WLSMV cannot be used for chi-square difference tests.
CFI/TLI CFI 0.968 TLI 0.983
Number of Free Parameters 8
RMSEA (Root Mean Square Error Of Approximation)
SRMR (Standardized Root Mean Square Residual) Value 0.039
WRMR (Weighted Root Mean Square Residual) Value 1.519
How do I interpret these results i.e., make sense of these results since they do not give me a coherent "story" of model fit or misfit?
bmuthen posted on Tuesday, September 13, 2005 - 4:33 pm
That's a big topic that have been discussed in several places, including on SEMNET and lots of SEM lit. See also Yu's dissertation which is on our web site. A rough way to handle this is to place (much) less emphasis on chi-square and WRMR (WRMR is often acting differently than other fit indices we have found more recently). From this perspective your model would appear to fit rather well. But it is good to search for neighboring models that fit better.