Re: st: RE: FW: Running Polychoric Principal Component Analysis in STATA

["Joseph Coveney" <jcoveney@bigplanet.com>]

In addition to Cameron's references for parallel analysis, there is also a
user-written Stata command -paran- and corresponding write-up in _The Stata
Journal_ ( http://www.stata-journal.com/article.html?article=st0166 ).  -findit
paran- brings up a couple of sources:  SSC and another on author's website,
which I assume is more up-to-date.  

It's not specifically intended for ordered polytomous variables and I don't know
how well its parallel analysis methods fare in comparison to those of articles
in Cameron's list that are focused on categorical variables.  

-paran- calls the official Stata command -pca-, and without alteration it would
not work with -polychoricpca-.  If I understand -paran-'s licensing correctly,
you can make a copy of the ado-file and modify the copy to instead call
-polychoricpca- and use its returned matrices.  I don't know how much effort
that would be.

Joseph Coveney


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