Date: Wed, 30 Sep 2009 19:22:07 -0400
Reply-To: Peter Flom <email@example.com>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Peter Flom <peterflomconsulting@MINDSPRING.COM>
Subject: Re: Poisson
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>On Wed, Sep 30, 2009 at 3:33 PM, Shawn Haskell (I think) wrote
>> very good - thanks for that WenSui. What's the latest on under-
>> dispersion if you can help there too? I have counts (response
>> variable) of 0-4. It is not a ZIP situation, and deviance/df < 0.5.
>> The scale parameter being <1 artificially reduces Type-3 SEs and p-
>> values. So, I switched to an ordinal logistic model that seems to fit
>> the data much better according to AICc. Any other thoughts? thanks.
Could I ask what your DV is? I haven't run into an underdispersion case.
Peter L. Flom, PhD
Website: www DOT peterflomconsulting DOT com