Date:         Sun, 20 Apr 2003 08:46:24 +0100
Reply-To:     jmcconnell@sigdiff.com
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         John McConnell <jmcconnell@sigdiff.com>
Subject:      Re: classification tree analysis
Comments: To: Art@DrKendall.org
In-Reply-To:  <3EA17E61.9040607@DrKendall.org>
Content-Type: text/plain; charset="us-ascii"

...and Bruce, if you are looking to generate the kind of Hierarchical
tree that Art describes, or more specifically a "Classification tree" as
in the explicitly named "Classification and Regression Tree (C&RT)" then
you find these in the SPSS Answer Tree product. Answer Tree is a
separate product but it installs an interface in the main SPSS menu.

It also has 3 other tree algorithms which, generically, can be thought
of as classification trees. These are CHAID, Exhaustive CHAID and Quest.
All 4 generate a tree diagram.

Cheers
John

John McConnell
Significant Difference

-----Original Message-----
From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of
Arthur J. Kendall
Sent: 19 April 2003 17:51
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: Re: classification tree analysis

Different disciplines use different vocabularies, please give more
details about your questions.
For example:
Do you want to create a hierarchical tree of the order cases are
agglomerated using a particular set of variables? e.g., create a new
nominal level variable based on a slice through that tree?

Or do you have a nominal level variable and want to explore what
differentiates the values of that variable allowing a tree structure
among the predictors?

What questions are you trying to answer with the data?

How many cases do you have? What constitutes a case in your data?

What variables do you have? What are their levels of measurement?

Do you wish to test some hypotheses?

Is the data already in an SPSS data file?

Hope this helps.

Art
Art@DrKendall.org
Social Research Consultants
University Park, MD USA
(301) 864-5570



WCS-Belize wrote:
> I need to do some classification tree analysis.  Can this be
accomplished
> in SPSS 10?
>
>  From what I have seen the algorithms were included in SPSS but help
is no
> help and does not tell me anything.
>
>
>
> Bruce W. Miller
> Associate Conservation Zoologist
> Wildlife Conservation Society
> (founded in 1895 as the New York Zoological Society)
> Gallon Jug, Belize
>
> Mailing address
> P.O. Box 37, Belize City
> Belize, Central America
> NEW Phone/Fax +501-220-9002
> Visit the
> Belize Biodiversity Information System
>  or the
> Neotropical Bat Information System
> at
> http://fwie.fw.vt.edu/wcs/
> OR
> Check out the WCS web site at: http://www.wcs.org
> OR
> Check out information on the Jaguar Conservation Program at
> http://www.savethejaguar.com
>