I have questions about the use of estimation. I checked the univariate and multivariate normality for 6 items that are 5-point Likert scale.
However, univariate and multivariate normality were violated. Therefore, I used MLR and WLSMV estimators to run 1-factor CFA when I treated the data are continuous. It turned out that WLSMV showed the best model fit compared with MLR : CFI:0.994,TLI:0.988, RMSEA:0.052,SRMS=0.041, and loadings are high.
In addition, I used WLSMV estimators to run 1-factor CFA when I treated the data are categorical. The results showed that CFI: 0.994, TLI:0.990, RMSEA:0.108, SRMS=0.044 and loadings are high. The value of RMSEA is too high compared with the situation where I used WLSMV estimation to treat the data are continuous.
My question is that : Could WLSMV be applied in the continuous data (i.e. 5-pint Likert scale) when data are not normal? Because I thought that WLSMV only could be applied in the categorical data.
Could WLSMV be applied in the continuous data (i.e. 5-pint Likert scale) when data are not normal? Because I thought that WLSMV only could be applied in the categorical data.
estimator = "DWLS" # only used for categorical data
se = "robust"
test = "scaled.shifted"
Thank you!
I am still a bit confused about WLSMV. Could WLSMV be applied in continuous data as well as categorical data?
In the following code, I used the WLSMV estimator, but it did not treat data as categorical data:
model<-'QoLIBRI=~q10+q11+q12+q13+q14+q15'
fit_WLSMV<-cfa(model=model,data=All,estimator="WLSMV")
Another code,I used the WLSMV estimator, but it treated data as categorical data:
model<-'QoLIBRI=~q10+q11+q12+q13+q14+q15'
fit_WLSMV<-cfa(model=model,data=All,ordered
=Items,estimator="WLSMV")
Also, are the following two codes using the same WLSMV estimation based on the same CFA model?
model<-'QoLIBRI=~q10+q11+q12+q13+q14+q15'
fit_WLSMV<-cfa(model=model,data=All,ordered =Items,estimator="WLSMV")
fit_mplus<-cfa(model = model,estimator="DWLS", se = "robust.sem", test = "scaled.shifted",parameterization="theta",
ordered = Items,data=All)
Could WLSMV be applied in continuous data as well as categorical data?
Adding test = "scaled.shifted",parameterization="theta" when estimating a model with ordered = TRUE (and estimator = DWLS) changes the results.This makes me confused what Terrence means by "DWLS and theta parameterization were developed for the application of covariance structure models to ordinal data."Do you mind explaining what do you meant, Terrence?