You are here

Scaled chi-square

3 posts / 0 new
Last post
falkcarl's picture
Offline
Joined: 10/29/2015 - 17:22
Scaled chi-square

Hi all,

Wondering if Satorra / Satorra-Bentler scaled chi-square is available in OpenMx or not? i.e., ML with robust corrections to the test statistics and standard errors in the case of non-normal data. Ideally, I'd like to see if the difference test for model comparisons is available. Only thing I found in the forums was this post from quite a while ago: https://openmx.ssri.psu.edu/thread/530

Many thanks!
Carl

AdminRobK's picture
Online
Joined: 01/24/2014 - 12:15
It's not built in to OpenMx,

It's not built in to OpenMx, though it sounds like it could potentially be a useful feature.

neale's picture
Offline
Joined: 07/31/2009 - 15:14
Agreed

I too think it could be useful in the armory of methods to deal with non-normality. A few riders though - non-normality often involves skewness so the utility of SE's (necessarily symmetric) becomes less (though likelihood-based CI's may still be useful). Second, careful inspection of how the data were obtained can often provide clues as to the source of non-normality, and in turn suggest alternative ways of dealing with it. A mixture of normal distributions, for example, may fit many observed distributions - and might provide insight into the generation of non-normality rather than sweeping it under the robust estimation rug. The drawback is it requires thinking :)