Date:         Tue, 29 Sep 2009 20:00:12 -0400
Reply-To:     Wensui Liu <liuwensui@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Wensui Liu <liuwensui@GMAIL.COM>
Subject:      Re: Poisson
Comments: To: "Reed, Derek" <derek.reed@sinclair.edu>
In-Reply-To:  <17CCBA5D887E2442A7CD5E9429A2A7682D6CBD@MAPLE.scc-nt.sinclair.edu>
Content-Type: text/plain; charset=ISO-8859-1

Derek,
You might want to take a look at my sugi paper in 2008. In my paper, I
provided several statistical tests for over-dispersion.

wensui

On Tue, Sep 29, 2009 at 10:40 AM, Reed, Derek <derek.reed@sinclair.edu> wrote:
> Morning Folks,
>
>
>
> In performing a Poisson regression using GENMOD, does anyone have a
> metric for how far is too far away from one for the scale parameter?  I
> am trying to decide when the data are too over dispersed.  When I re-run
> an analysis using the negative binomial distribution my 1.26 scale
> parameter becomes .80.  Any help/guidance would be appreciated.  Many
> thanks!
>
>
>
> Derek
>
>
>
>
>



--
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WenSui Liu
Blog   : statcompute.spaces.live.com
Tough Times Never Last. But Tough People Do.  - Robert Schuller
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