OK, I understand your proposition. Instead to use the matrix of the
tetrachoric correlations between my items, I used simulated dataset with a
correlation structure similar to this matrix.
It's interesting, but I don't know if this could be valid !!
For Stas Kolenikov, I'm interesting by your program about tetrachoric
correlations and PCA. Thank you to send it to me.
Jean-Benoit Hardouin
On Fri, 23 Jan 2004 09:32:45 -0500, Richard Williams
<[email protected]> wrote:
At 03:00 PM 1/23/2004 +0100, [email protected] wrote:
OK, thank you for your responses, but my question was not enough precise
:
I want to realize a factor analysis based on the tetrachoric
coefficients matrix WITH STATA. The Stata program tetrac (author :
Philip B. Ender) permit to create this matrix, but I don't know how
realize WITH STATA a factor analysis on a such matrix (the factor Stata
program don't permit to use a correlation matrix different of the
classical (pearson rho coefficients) correlation matrix). The procedure
"factor" of SAS, for example, permit to choose a dataset as the working
correlation matrix in defining
the dataset as a correlation matrix.
Jean, perhaps I wasn't clear, but -corr2data-is a Stata command. It is
quite useful when you have the means and covariances but not the original
data. In your case, it might be a way of faking Stata into analyzing
something other than the usual Pearson correlation matrix.
My one concern, as I said before, is that I am not sure whether factor
analysis using tetrachoric correlations only requires the input of the
tetrachoric correlations, or whether the computations are supposed to
proceed differently when you have tetrachoric correlations.
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Jean-Benoit Hardouin
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