Re: Q: dichotomous variables

John Uebersax <jsuebersax@xxxxxxxxx> wrote:

:Hi Erkii,

:> certain things in mind. Gorsuch (Factor Analysis 2nd Ed. , 1983) and
:> Rummel (Applied Factor Analysis, 1970) give such examples and present
:> some difficulties but do not deny the use of dichotomous variables
:> categorically. I know that LISREL, Mplus and other programs offer
:> sophisticated solutions to the problem.

:You have the option to factor analyze the matrix of tetrachoric
:correlation coefficients. I have a free program, TetMat, much simpler
:than LISREL or Mplus for this:

:http://ourworld.compuserve.com/homepages/jsuebersax/tetra.htm#soft

:Factor analysis of tetrachoric correlation coefficients is discussed
:here:

:http://ourworld.compuserve.com/homepages/jsuebersax/sem.htm

:Note than when Rummel and Gorsuch wrote their books, tetrachoric
:correlation coefficients were considered difficult to calculate. Now,
:with more software and better computers, that is trivial. In 1970,
:people were doing factor analysis with manual calculations!

:HTH

:John Uebersax PhD

Thanks John! Nice pages & lots of information!

--
Erkki
Mobile +358 40 5024491 <http://www.helsinki.fi/~komulain/>
.