Message/Author 

Qi posted on Thursday, October 02, 2008  1:48 pm



is the "ChiSquare Test of Model Fit for the Baseline Model" in Mplus comparable to the "ChiSquare for Independence Model" in LISREL 8.53? I want to make sure in both software I am running the same model by comparing the baseline model's df and Chisquare value, but it seems that I heard that the baseline model in Mplus is a little different (so it can result in different CFI fit stat value). How different is it? Thanks for your advice! 


Where y represents dependent variables and x represents independent variables, the Mplus baseline model is: y with y is zero y with x is zero x with x is not zero The LISREL baseline model is: y with y is zero y with x is zero x with x is zero Because the LISREL baseline model fits very poorly, model fit is exaggerated. 

Yue Yin posted on Thursday, November 09, 2017  1:13 pm



How about if there are two x's? Is the correlation with x1 and x2 also 0? Or they stay the same ? 


"x with x is not zero" implies x1 with x2 not zero (but equal to sample covariance). 

Jing Davis posted on Thursday, June 21, 2018  8:38 am



Hi Dr. Muthen, I tried to run a bifactor model using all categorical variables. But, I got the resutls: The chisquare value for MLM, MLMV, MLR, ULSMV, WLSM and WLSMV cannot be used for chisquare difference testing in the regular way. MLM, MLR and WLSM chisquare difference testing is described on the Mplus website. MLMV, WLSMV, and ULSMV difference testing is done using the DIFFTEST option. I was wondering how to perform the DIFFTEST for the model fit. Do I need to run two different model twice  one is the bifactor model and the other is the baseline model so that the DIFFTEST can be computed? If so, what is the Baseline model of Bifactor model in Mplus? Thank you for your time in advance! 


DIFFTEST is needed only if you compare two "H0" models. If you want the chisquare for an H0 compared to the usual unrestricted H1 model, then you already have that in the regular output. 

Jing Davis posted on Friday, June 22, 2018  6:43 am



Hi Dr. Muthen, Thank you for the quick response. It is really helpful. In the Bifactor model analysis, the estimator method is WLSMV. So, I guess that is why in the output, there is a comment line under the Chisquare test of Model Fit. Please see the following comments. ChiSquare Test of Model Fit Value 232.077* Degrees of Freedom 187 PValue 0.0139 * The chisquare value for MLM, MLMV, MLR, ULSMV, WLSM and WLSMV cannot be used for chisquare difference testing in the regular way. MLM, MLR and WLSM chisquare difference testing is described on the Mplus website. MLMV, WLSMV, and ULSMV difference testing is done using the DIFFTEST option. RMSEA (Root Mean Square Error Of Approximation) Estimate 0.015 90 Percent C.I. 0.007 0.020 Probability RMSEA <= .05 1.000 CFI/TLI CFI 0.970 TLI 0.963 If I interpreted correctly, it looks like the Chisquare test indicates that the Model does not fit. But, the RMSEA says that the model fits well. Did I missing anything here? Again, thank you for your time. 


Fit indices often disagree. Look for ways to improve the chisquare fit by working with Modindices. 

Jing Davis posted on Monday, June 25, 2018  2:58 pm



Dr. Muthen, thank you for the clarification! I'll run the output with Modindices function to see how the results will look like. 

Jing Davis posted on Wednesday, June 27, 2018  8:42 am



Hi Dr. Muthen, I ran the command Modindices. In the output, there are 999 in almost everywhere under ON, WITH, and BY statement. The following are the excerpts from the output. From your answers to other posts' questions regarding the 999 in Modindices, I found that 999 means MI can not be computed. However, since my data are categorical, the estimation method is WLSMV. My question is: Can I still trust the results? How can I interpret it? Is 999 in this case due to the MI missing or there are some issues going on in the model I tried to fit. Thank you. ON/BY Statements V1 ON F1 / F1 BY V1 999.000 0.000 0.000 0.000 V1 ON G / G BY V1 999.000 0.000 0.000 0.000 ON Statements F1 ON V1 999.000 0.000 0.000 0.000 F1 ON V2 999.000 0.000 0.000 0.000 WITH Statements G WITH F1 999.000 0.000 0.000 0.000 G WITH F2 999.000 0.000 999.000 999.000 V1 WITH F1 999.000 0.000 0.000 0.000 V1 WITH G 999.000 0.000 0.000 0.000 V2 WITH F1 999.000 0.000 0.000 0.000 


Send your output to Support along with your license number. 

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