|Date: ||Wed, 10 Apr 2002 16:05:56 +0100|
|Reply-To: ||Jeremy Miles <firstname.lastname@example.org>|
|Sender: ||"SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>|
|From: ||Jeremy Miles <email@example.com>|
|Subject: ||Re: Gender codes|
|Content-Type: ||text/plain; charset="us-ascii"; format=flowed|
At 15:41 10/04/02, Beckman, Anthony wrote:
>I am looking at some code that was given to me for help in learning SPSS. I
>see within it a few lines of syntax that transforms gender values from 1=
>female and 2 = male to -1 = female and 1 = male.
>Any specific reasons why someone might do this? Does it help in running
Yes, using -1 and +1 is a type of coding for using categorical variables in
regression analysis - this is usually referred to as effect coding. Using
this method, the intercept becomes the mean of the DV.
Have a look at a book on regression for more info (or do a web search, that
would probably do the trick).
Department of Health Sciences, University of York, Heslington, York, YO10 5DD
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