sem - how to extract "chi square for each group:" values from lavaan when using known groups

I want to extract the individual group chi square values from lavaan output that is provided when conducting multiple, known group sem models. Only the total chi square is provided as a fitMeasure, and the chi square values are not treated as individual estimates in parameterEstimates. There doesn't appear to be any other automated method for extracting this information.I have been able to use the capture.output() function, and from there I can find the heading for the chi square values, and count the number of lines of values based on the numb...Read more

Estimation of direct and total effects with regressions and SEM (lavaan)

I am reading about the mediation test example from the lavaan package here:http://lavaan.ugent.be/tutorial/mediation.htmlSpecifically, they fit the model:set.seed(1234)X <- rnorm(100)M <- 0.5*X + rnorm(100)Y <- 0.7*M + rnorm(100)Data <- data.frame(X = X, Y = Y, M = M)model <- ' # direct effect Y ~ c*X # mediator M ~ a*X Y ~ b*M # indirect effect (a*b) ab := a*b # total effect total := c + (a*b) 'fit <- sem(model, data = Data)summa...Read more

sem - lavaan WLSMV estimator: are results reliable when number of observations is too small to compute Gamma?

I run CFA (confirmatory factor analysis) with WLSMV estimator (since my data are ordinal) in lavaan and I get the following warning message:number of observations (190) too small to compute GammaIs this a problem with Gamma only and the rest is computed correctly? Can I proceed with results obtained with this warning? E.g. interpret estimates, p-values and fit indices in usual way? Or maybe this affects somehow (how?) credibility of a whole CFA?...Read more

confirmatory factor - Does a poorly fitting CFA preclude SEM?

Trying to help someone with a Masters dissertation.I've run CFA in Jamovi on her questionnaire responses based on the assumed item/factor relationships.I don't really understand the various outputs from the Jamovi CFA program,and havn't so far been able to locate an idiot's guide. She certainly doesn't understand them, and its a fair bet that her supervisor won't understand them either, but apparently she's likely to have an external examiner who is not clueless, so the default reliance on "emperors new clothes" may be risky.I get a poor fit on...Read more

sem - Help moving forward after modIndices() in lavaan

I’m running a model in SEM using lavaan. I’ve really run into a puzzle I can’t quite seem to solve and I would love to tap into everyone’s expertise to help provide some direction. Below I’ve added the steps I’ve taken so far to help shed light on my attempt at Sherlock Holms-ing this situation. Apologies in advance for the length of the post, but hopefully there’s some other brains out there that thrive on solving problems like these.Please see the image below for my original model. The model is pretty basic with latent variable RL (responsive...Read more

sem - Difference between PLS regression and PLS path modeling. Criticism of PLS

This question was asked here but no one gave a good answer. So I think it's a good idea to bring it up again and also I would like to add some more comments/questions. The first question is what is the difference between "PLS path modeling" and "PLS regression"? To make it more general, what are structural equation modeling (SEM), path modeling and regression? To my understanding regression focuses more on prediction while SEM focus is on the relationship between response and predictors and path modeling is a special case of SEM? My second ques...Read more

partial least squares - How to interpret weights of a PLS SEM model

I made a PLS SEM model using smartPLS, consisting only of formative constructs. I managed to get weights out of the software, which all had excellent t values. The only thing is, I am not entirely sure how to interpret these values. Unfortunately, the internet cannot provide me with an unambiguously answer. I hope you guys can help me out. This is the model...Read more