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Hi, I am using SEM to explore a mediation model. The observed variables are binary/ordinal (while the latent variables are continuous). I am using the default estimator: WLSMV. I would like to use bootstrap on the data; but when I add analtsis: type = bootstrap, MPlus does not produce the model estimates. Well below is what I obtain from the output: THE MODEL ESTIMATION TERMINATED NORMALLY TESTS OF MODEL FIT Number of Free Parameters 100 RMSEA (Root Mean Square Error Of Approximation) Estimate 0.000 WRMR (Weighted Root Mean Square Residual) Value 1.407 Can anyone tell me why I am receiving such input and whether it is possible to use the bootstrap option and still obtain the chisquare and CFI model fit indices? Many thanks 


TYPE = BOOTSTRAP does not exist in the Mplus language. It is BOOTSTRAP = the number of bootstrap draws you want, for example, BOOTSTRAP = 100; 


Hi Linda, Thanks for your promt response. When I use: Analysis: bootstrap=100; I still experience the same problem, i.e. the output does not produce chi square or CFI as model fit indices  but just the output as in my earlier message. Is it because I am using WLSMV? 


Please send the output and your license number to support@statmodel.com. 


Hi, I have the same problem. I am using SEM to explore a mediation model. The observed variables are binary/ordinal . I am using the default estimator: WLSMV. I would like to use bootstrap on the data; but when I add analysis: estimator=wlsmv; bootstrap = 1000; , MPlus does not produce the model estimates. Well below is what I obtain from the output: THE MODEL ESTIMATION TERMINATED NORMALLY MODEL FIT INFORMATION Number of Free Parameters 269 WRMR (Weighted Root Mean Square Residual) Value 0.721 Can anyone tell me why I am receiving such input and whether it is possible to use the bootstrap option and still obtain the chisquare and CFI model fit indices? Many thanks 


Only the standard errors are bootstrapped not the fit indices. If you want the regular, not bootstrapped, fit statistics, run the analysis without the BOOTSTRAP option. 


Hey, I have the same problem. Is it possible to run the analysis without the bootstrap option even the sample is very small (n=80). Or what do you mean with the sentence 'run the analysis without the BOOTSTRAP option'. But I thought, that I have to do bootstrapping, if my sample is to small?! So I am not sure what I have to report. Or is the information about the wrmr enough, if I use bootstrapping? Thank you very much!!! 


The BOOTSTRAP option applies to standard errors not fit statistics. If you want fit statistics, remove the BOOTSTRAP option and you will obtain nonbootstrapped fit statistics. Use the results from the bootstrapped standard errors along with the nonbootstrapped fit statistics. Your small sample will result in lower power. 

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