Dear Lavaan group,
I am testing measurement invariance across gender group for a second-order factor model. I am comparing the significant difference in chi-square between configuration invariance model and weak invariance model (invariance of 1st factor loadings). The variables tested in my model are all continuous. I used lavTestLRT(). More specifically, my syntax is lavTestLRT(modelconfig, modelweak1st, SB.classic = TRUE). However, lavaan told me that:
"Error in lavTestLRT(modelAgg3f3, modelAgg3f4, SB.classic = TRUE) :
trying to get slot "optim" from an object of a basic class ("character") with no slots"
I am not familiar with comparing model difference for second-order factor model. Can you please help me fix the problem so that I am able to do the comparison?
Thank you very much in advance for considering my request,