Right, when all variables are dichotome CATPCA is equal to linear PCA.
(with only 2 categories any transformation is linear, because between
2 points you can only fit a straight line).
Anita van der Kooij
Data Theory Group
Leiden University
________________________________
From: SPSSX(r) Discussion on behalf of Erkki Komulainen
Sent: Fri 25/04/2008 19:13
To:
[hidden email]
Subject: factoring dichotomous response
Hi!
When all the variables are dichotomies CATPCA seems to be PCA
(principal component analysis) but without the possibility to
rotate the components? Or am I missihg something basic?
Comrey in his First Course in Factor Analysis (1973) gives some
noteworthy points when dealing with dichotomies. So do Rummell
and Goresuch as well. In EFA there is only little development
since those days.
More is going on in CFA/SEM and it could be a good idea to look
at the archives of SEMNET.
Regards
--
Erkki
Mobile +358 40 5024491 <
http://www.helsinki.fi/~komulain/>
=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD
**********************************************************************
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error please notify
the system manager.
**********************************************************************
====================To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD
Locked
