Date:         Fri, 11 Jan 2008 08:41:53 -0500
Reply-To:     Art@DrKendall.org
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Art Kendall <Arthur.Kendall@verizon.net>
Subject:      Re: Running a Stepwise Regression Model
Comments: To: Donna Daniels <ddani001@waldenu.edu>
In-Reply-To:  <47862D0E.8060705@waldenu.edu>
Content-type: text/plain; charset=ISO-8859-1; format=flowed

A stepwise regression is not usually a good idea.
some ideas to consider:
A. try using theory to reduce the number of predictors.

B. use some form of factor analysis (PCA or PAF) to get  a smaller
number of predictors.

C. consider a stepped/hierarchical approach.
for each variable show
1) the zero-order correlation with the DV. i.e., 1 predictor at a time.
(max fit)
2) the b&beta when all 7 variables are in the equation - 7 predictors.
(fit when all are in at the same time)
3) the change in fit and b&beta  when 6 variables are ENTERed in 1 step
and the 7th is ENTERed on the second step. Unique contribution to fit.

for syntax, case studies, and tutorials see the <help> command.

Art Kendall
Social Research Consultants


Donna Daniels wrote:
> I am having difficulty running the Stepwise Regression Model on my SPSS
> 14 package.  My dissertation research has seven independent variables
> that could be related to each other causing multicollinearity issues.
> To avoid multicollinearity, I chose the stepwise model.  Could someone
> send me the command I need to use to make this work?
>
> Thank You,
>
> Donna Daniels
> Doctoral Candidate
>
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