Date: Wed, 21 Sep 2005 13:53:29 -0500
Reply-To: Vishal Dave <VishalDave@Affina.com>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Vishal Dave <VishalDave@Affina.com>
Subject: Re: Regresssion Plot in SPSS
Content-Type: text/plain; charset="iso-8859-1"
Karl,
Since your variables are not standardized, the coefficients won't add up to 1.0. You have to covert the variables in standardized variables and then run the regression model. It will give you model with intercept = 0 and sum(coefficients) = 1. This will also take care of having different non-standardized variables with different mean and SD.
Vishal.
-----Original Message-----
From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of Karl Koch
Sent: Wednesday, September 21, 2005 12:48 PM
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: Re: Regresssion Plot in SPSS
So, what you are saying is I have to create first a new regression model
that only includes A and C. Then only use the unstandarized regression
coefficients. Did I understand you correctly?
What is the difference to the standarized coefficients? Do the standarized
coefficients somehow add up to 1.0 so that they can be seen as percentage of
magnitiude?
Kind Regards,
Karl
> --- Ursprüngliche Nachricht ---
> Von: "Swank, Paul R" <Paul.R.Swank@uth.tmc.edu>
> An: SPSSX-L@LISTSERV.UGA.EDU
> Betreff: Re: Regresssion Plot in SPSS
> Datum: Wed, 21 Sep 2005 12:35:19 -0500
>
> No, you are using the unstandardized intercept but the standardized
> regression coefficients. And because B may bias the weights for A and C,
you need
> to run the regression again without B. The coefficients for Aand C will
> likely change. Then use the unstandardized coefficients for the regression
> equation.
>
>
> Paul R. Swank, Ph.D.
> Professor, Developmental Pediatrics
> Director of Research, Center for Improving the Readiness of Children for
> Learning and Education (C.I.R.C.L.E.)
> Medical School
> UT Health Science Center at Houston
>
> -----Original Message-----
> From: Karl Koch [mailto:TheRanger@gmx.net]
> Sent: Wednesday, September 21, 2005 10:36 AM
> To: Swank, Paul R; Mailinglist SPSS
> Subject: RE: Regresssion Plot in SPSS
>
> Hello Paul,
>
> Yes, I agree. Given the fact that now I only have two paramters left
> (=being significant), is this the correct equation (keeping in mind the
table
> below)?
>
> Y = 4.195 - 0.319 * A - 0.442 * C + e
>
> What would be e in this case? I have standard erros for each parameter...
>
> Kind Regards,
> Karl
>
> ----------------------------------------------------------------
> Model Unstd. Coeff. Std. Coeff. t Sig.
> B Std. Error Beta
> -----------------------------------------------------------------
> 1(Constant) 4.195 .070 58.971 .000
> A -.779 .042 -.319 -18.278 .000
> B -.028 .046 -.010 -.618 .534
> C -1.635 .064 -.442 -25.354 .000
> -----------------------------------------------------------------
>
>
> >
> > Drop B from the model first as it could bias the parameters for A and C.
> >
>
> --
> 5 GB Mailbox, 50 FreeSMS http://www.gmx.net/de/go/promail
> +++ GMX - die erste Adresse für Mail, Message, More +++
>
--
5 GB Mailbox, 50 FreeSMS http://www.gmx.net/de/go/promail
+++ GMX - die erste Adresse für Mail, Message, More +++
| 
