Date:         Wed, 15 Nov 2006 06:20:41 -0500
Reply-To:     Statisticsdoc <statisticsdoc@cox.net>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Statisticsdoc <statisticsdoc@cox.net>
Subject:      Re: PCA factor score uses?
Comments: To: "Fredric E. Rose" <frose@palomar.edu>
In-Reply-To:  <C17FC6F8.1857%frose@palomar.edu>
Content-Type: text/plain; charset="us-ascii"

Fred,

Yes, the scores can be used as dependent variables.

Factor scores are standardized with Mean = 0 and SD = 1 , so your groups are
quite different from one another.

Best,

Stephen Brand

For personalized and professional consultation in statistics and research
design, visit
www.statisticsdoc.com


-----Original Message-----
From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU]On Behalf Of
Fredric E. Rose
Sent: Tuesday, November 14, 2006 10:18 PM
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: PCA factor score uses?


I'm not entirely familiar with PCA and could use some help.

I've used PCA w/varimax rotation to reduce 10 variables (answers to a racism
attitudes questionnaire) down to 2 factors.  I want to know if the
calculated factor scores for each participant can then be used as a
dependent variable in subsequent analyses, or whether I should simply
combine the variables loading on the respective factors and use those?  My
problem is in interpreting the factor scores:  Group 1 has a mean of -2.72
and Group 2 has a mean of 2.68.  These are significantly different, but I'm
not sure what the means represent (the raw data are scores ranging from 1 to
10, so there are no negatives).

Thanks for any insight.

Fred Rose