Date: Wed, 29 Apr 1998 16:16:29 -0400
Reply-To: "William B. Ware" <wbware@EMAIL.UNC.EDU>
Sender: "SPSSX(r) Discussion" <SPSSX-L@UGA.CC.UGA.EDU>
From: "William B. Ware" <wbware@EMAIL.UNC.EDU>
Subject: Re: Clarification of Factor analysis problem
In-Reply-To: <c=US%a=_%p=BROOKSAFB%l=BASIA-980429195054Z-1456@basia.brooks.af.mil>
Content-Type: TEXT/PLAIN; charset=US-ASCII
On Wed, 29 Apr 1998, Thompson, Bill T. wrote:
> My apologies for being unclear. The study looked at differences between
> three groups:
>
> 1. Control
> 2. Attention deficit disorder on medication
> 3. Attention deficit disorder off medication
From this, I gather that these are three "independent groups"...
> The dependent variables were 19 brain sites from EEG data collection
> system.
> The purpose of performing the Factor analysis was to see if the activity
> with various brain sites grouped together in any meaningful way among
> the varyous groups. Therefore, by example,
>
> Trial 1 Group 1
> Factor 1 sites 1-10
> Factor 2 sites 11-15
> Factor 3 sites 16-19
>
> Trial 1 Group 2
> Factor 1 sites 1-13
> Factor 2 sites 14-19
>
> Trial 1 Group 3
> Factor 1 sites 14-19
> Factor 2 sites 11-13
> Factor 3 sites 1-10
Based on what I see, there might be two "factors" which could be
considered "consistent" across the three groups... Factor A could be
comprised of sites 1-10, and Factor B could be sites 16-19. Sites 11-15
appear to be inconsistent... which of course, might be interesting in and
of itself... but if you are interested in comparing the three groups, I
suggest that you use "my" factors A & B...
__________________________________________________________________________
William B. Ware, Professor and Chair Psychological Studies
CB# 3500 in Education
University of North Carolina PHONE (919)-962-7848
Chapel Hill, NC 27599-3500 FAX: (919)-962-1533
http://www.unc.edu/~wbware/ EMAIL: wbware@unc.edu
__________________________________________________________________________
