Bayesian SEM: LOO-CV / Fit Measures

Question

I am running various bayesian path models in r ('blavaan' package). I understand that LOO is a more robust fit index when working with a smaller samples size (and weakly informative priors). I am using LOO-CV (PSIS) method to compare path models; however, I have additional questions.

1. How do I interpret LOO-CV values to determine which model has the better fit?
2. Should multiple fit indices be present in bayesian SEM results?
3. Is there an alternative r package that runs 'loo-cv' analyses? The "loo" package will not load.

Thank you.

Answer 1

1. LOO-CV works like an information criterion (lowest value wins): for comparison, not an index for evaluating fit in an absolute sense.
2. "present"? Multiple are available.
3. blavaan provides the DIC, WAIC, and LOO-IC (approximation to LOO-CV) via the loo package. If you have trouble with installing it, that is a separate issue to post about (e.g., on StackOverflow, or the Stan forum). You can read through all their introductory information on the blavaan web site.