Hi Mike;
I have three questions regarding TSSEM for testing a fully mediated structural model. I will appreciate your advice.
(1) A problem I am facing now is that all goodness of fit indices are showing an acceptable fit for my model in tssem2() except SRMR, which is 0.109. I know that in your 2009 paper published in Structural Equation Modeling you have discussed that some of the goodness of fit indices such as CFI might be slightly inflated in tssem due to the two stages as well as the wls estimation method. Is this logic generalizable to SRMR as well? or is there any other reason for a higher SRMR estimate as compared to other goodness of fit indices?
(2) Do you have any suggestion for generating additional goodness of fit indices, besides the ones generated by tssem2(), such as GFI, AGFI, and IFI?
(3) When I test my fully mediated model using (diag.constraints=FALSE, intervals.type="z") the results make sense and they are very stable. However, changing it to (diag.constraints=TRUE, intervals.type="LB") results in OpenMx status1: 4 (and 6 after rerun()) and it generates many NA for lbound and ubound values. I was wondering whether it is safe to report the results based on (diag.constraints=FALSE, intervals.type="z"), given their stability and interpretability.
Thank you for your help in advance,
Hamed