Dear Allan, I assume that the categorical data are ordinal. There are methods for factor analyzing ordinal data (e.g., using polychoric correlations) and mixed ordinal and interval data, but as far as I know, these aren't implemented in R.
John On Thu, 13 May 2004 18:32:11 +0200 allan clark <[EMAIL PROTECTED]> wrote: > hi all > > this is a stats question. > > when undertaking factor analysis should the variables included always > be > continiuos random variables? could one include categorical data? e.g > some survey type data > > my gut feeling is that one should not include categorical type data > since factor analysis is based on the eigenanalysis of the > correlation > matrix of a group of variables. The introduction of categorical data > into a data set might "mess up" the corelation matrix. > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html -------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox/ ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
