[R] No fit statistics for some models using sem

Hi, New to both R and SEM, so this may be a very simple question. I am trying to run a very simple path analysis using the sem package. There are 2 exogenous (FARSCH, LOCUS10) and 2 endogenous (T_ATTENT, RMTEST) observed variables in the model. The idea is that T_ATTENT mediates the

Re: [R] No fit statistics for some models using sem

It's not the correlation as such that is the problem; it's because you only have 10 degrees of freedom available with four observed variables, and you are estimating 10 parameters, which is why you get a chi square of zero. When you remove any one free parameter (such as the correlation), the

Re: [R] No fit statistics for some models using sem

Dear David and Ista, I haven't looked at this model carefully, but the fact that the df are 0 suggests that the model is just-identified and therefore necessarily perfectly reproduces the covariances among the observed variables. Removing a parameter would over-identify the model, making possible