rgrove posted on Wednesday, August 17, 2011 - 6:01 pm
I am wondreing whether anyone can help me to understand the impact that a multigroup analysis has on a RMSEA.
The RMSEA values for a two factor model is 0.00 for my three groups when I look at them individually but this is increased to 0.098 when I conduct the multigroup analysis. All other fit indices are within the specified cut-offs.
Is this an artifact of the increase in the sample size? Or does this mean that the model is not interpretable.
I assume your multiple-group model imposes some invariance constraints on the parameters, so the worsening RMSEA may be a reflection of that.
rgrove posted on Wednesday, August 17, 2011 - 8:38 pm
Thanks for getting back to me. The model is the 1st step in that it is the same model across the three groups allowing the factor loadings to vary. I guess I'm wondering whether I am still able to write this up as a good model considering the large RMSEA value?
Sorry, I was thinking SRMR. Why don't you post your full set of fit indices?
rgrove posted on Thursday, August 18, 2011 - 12:40 am
So for my two factor models across the separate groups (df = 1, free parameters = 13, N = 232, 298, 363) the fit statistics are as follows: Chi-square = 1.8, 0.2, 0.4, RMSEA = 0.00, CFI = 1.00, TLI = 1.01
And for the multigroup (df = 8, free parameters = 34, N = 893) they are as follows: Chi-square = 30.8**, RMSEA = 0.098, CFI = 0.984, TLI = 0.964