| Date: | Tue, 14 May 1996 17:11:22 UNDEFINED |
| Reply-To: | "Stuart E. Wugalter" <swugalt@CALSTATELA.EDU> |
| Sender: | "SPSSX(r) Discussion" <SPSSX-L@UGA.CC.UGA.EDU> |
| From: | "Stuart E. Wugalter" <swugalt@CALSTATELA.EDU> |
| Organization: | California State University Los Angeles |
| Subject: | Re: Stepwise regression with categorical variables |
|---|
In article <4na9mo$dbc@netsrv2.spss.com> nichols@spss.com (David Nichols)
writes:
>The REGRESSION procedure in SPSS does not explicitly handle categorical
>variables, so it's not possible to just let fly with a stepwise with
>categorical predictors with more than two categories. Newer nonlinear
>regression procedures such as LOGISTIC REGRESSION and COX REGRESSION
>have automatic handling of categorical variables, but REGRESSION does
>not at the current time have this capability. You can, of course, do
>what a stepwise analysis does "by hand," using multiple runs to get the
>same results. It's tedious, but it's the only way.
>--
>-----------------------------------------------------------------------------
>David Nichols Senior Support Statistician SPSS, Inc.
>Phone: (312) 329-3684 Internet: nichols@spss.com Fax: (312) 329-3668
>-----------------------------------------------------------------------------
Hmmm....can't you get what you want with effects coding or some other coding
scheme? I thought I remember learning this in regression class some years ago.
The more serious problem with the study though is alluded to by the
consultant: stepwise regression. I cannot think of any reason to use it. I
wish SPSS & others would just remove this feature. Its just another excuse not
to think about what you are doing.
Stuart E. Wugalter
Curmudgeon Statistical Computing Consultant, CalStateLA
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