Date:         Tue, 6 May 1997 21:27:48 GMT
Reply-To:     Edward Malthouse <ecm@NWU.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Edward Malthouse <ecm@NWU.EDU>
Organization: Northwestern University
Subject:      Re: chaid on sas

I have used SPSS' version of CHAID and found it to be very dangerous.  The
problem I have with it is that it is prone to overfitting the data -- I get a
nice tree and decent fit statistics, but when I apply it to another data set
the predictions are not so good.
 
I have had much better luck with Splus' CART (classification and regression
trees is an improved version of chaid) functionality.  It includes options
that automate the process of validating the model with holdout samples.
 
I sincerely hope that SAS does not follow SPSS' model for CHAID.
 
Ed Malthouse
 
 
In article <19970430.161151.580850.NETNEWS@AUVM.AMERICAN.EDU>,
   "Zhang, Alex - O&MD NY" <OGILVY!OMDNY1!ZHANGAL@OMDNY.ATTMAIL.COM> wrote:
>I was told at a SAS seminar about a month ago that CHAID and neural network
>are only available through SI's Professional Service as part of the
>customized packages.  SI is planning to release a data mining product which
>will include CHAID at the end of this year.  A beta version may be available
>as early as this Summer.
>
>Alex Zhang
>Ogilvy & Mather Direct
>alex.zhang@OGILVY.COM
> ----------
>From: Philip Holland
>To: Multiple recipients of list SAS-L; ZHANGAL
>Subject: Re: chaid on sas
>Date: Wednesday, April 30, 1997 4:54PM
>
>skmxx <skmxx@ibm.net> wrote:
>>Hi! everyone.
>>
>>I need your advice.  I want to run CHAID on sas, but, I cannot find
>>where. In sas/stat manual I could not find any word CHAID on the index.
>>I know there is CHAID option on spss. On sas where is this option or
>>comparable option?  I really appreciate your advice.
>>
>>Soo Hong Kim
>>Graduate Student
>>Syracuse Univ.
>
>I believe there are some SAS macros for CHAID stats
>processing, supplied by the SAS Institute.  I suggest you
>contact your local SAS office, but be warned that they may not
>be free...
>
>HTH..............Philip R Holland <phil.holland@bcs.org.uk>
>                 Holland Numerics Ltd
>                 Royston, Herts, UK
>                 mobile: +44-(0)850-295556
 
Edward Malthouse
Assistant Professor
IMC Department
Medill School of Journalism
Northwestern University
Evanston, Illinois
ecm@nwu.edu