Date:         Thu, 22 May 2008 11:34:32 -0500
Reply-To:     Citam <citam.sasl@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Citam <citam.sasl@GMAIL.COM>
Subject:      Re: GENMOD Poisson
In-Reply-To:  <CA8F89971ADA9F47A6C915BA2397844207B427DD@MAILBE2.westat.com>
Content-Type: text/plain; charset=ISO-8859-1

On 5/21/08, Sigurd Hermansen <HERMANS1@westat.com> wrote:
> No. While aggregation makes data more compact, you don't have to
> aggregate into events/trials form.
>
> SAS documentation shows the response = effects alternative to the
> events/trials syntax of the MODEL statement:
> MODEL response = < effects > < /options > ;
>
>   as opposed to
>
> MODEL events/trials = < effects > < /options > ;

Thanks Sig.  It seems that when I use the stratification A*B*C to
aggregate (sum), and then leave C out of the model, the DF change,
given that C has more than one level.  I will have to look into the
documentation further and hopefully find a book in our library that
specifically address poisson regression using GENMOD.


A B  C
0  0  0
0  0  1

1  0  0
1  0  1