need help with factor analysis of matrix of polychoric correlations

have ordinal rating scale data on a moderate mumber of items and I
would like to extract a few common factors from the data. I've used
the SAS macro %polychor to create a matrix of polychoric
correlations.
However, when I try to perform the factor analysis, I get strange
results. The first eigenvalue accounts for 99% of the variation in
the
correlation matrix and all the variables load on that factor almost
exclusively. Examining the polychoric correlation matrix produced by
%polychor suggests this is just
not so, but I don't have any idea what I'm doing wrong. I can send
the
correlation matrix to anyone who may have an idea how to make the
thing work.

Thanks,
Mark Schultz
.

Relevant Pages

  • Re: FA vs. PCA and grouped vs. non-grouped
    ... I'm familiar with the SAS Polychor macro. ... repeatedly invoke PROC FREQ with the PLCORR option. ... calculate a correlation matrix, including polychoric and tetrachoric ... it comes to estimating factor loadings. ...
    (sci.stat.consult)
  • Re: need help with factor analysis of matrix of polychoric correlations
    ... If you would like to drop me an email maybe I could make a suggestion. ... that something is amiss with the polychoric correlation coefficients. ... the SAS macro %polychor to create a matrix of polychoric ... Examining the polychoric correlation matrix produced by ...
    (sci.stat.math)