Message-ID: <A43C9B08-8098-470F-B153-DA9077F71622@anu.edu.au>
Date: 2010-08-05T22:31:09Z
From: John Maindonald
Subject: checking for overdispersion in lmer?
In-Reply-To: <10D639E2-2783-479D-A37A-D4E6938F070E@gmail.com>
The totals (input as weights if you are fitting proportions) need
to be supplied, with family=binomial. You need to model the
extra variance, with observation level random effects. If you
need an example, some of can supply one. I gave an example
for overdispersed Poisson in a Dec 12 message last year.
John Maindonald email: john.maindonald at anu.edu.au
phone : +61 2 (6125)3473 fax : +61 2(6125)5549
Centre for Mathematics & Its Applications, Room 1194,
John Dedman Mathematical Sciences Building (Building 27)
Australian National University, Canberra ACT 0200.
http://www.maths.anu.edu.au/~johnm
On 05/08/2010, at 11:37 PM, touchtonj wrote:
> Hello,
>
> How can I check for overdispersion in a lmer with proportion data? There is no residual deviance output like in a glm
>
> thanks ~ janeene
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