R help - Nov 2009 - overdispersion and quasibinomial model

I am looking for the correct commands to do the following things:

1. I have a binomial logistic regression model and i want to test for
overdispersion.
2. If I do indeed have overdispersion i need to then run a quasi-binomial
model, but I'm not sure of the command.
3. I can get the residuals of the model, but i need to then apply a shapiro
wilk test to test them. Does anyone know the command for this?

Any help would be hugely appreciated,

Thanks,

Djp


-- 
View this message in context:
http://old.nabble.com/overdispersion-and-quasibinomial-model-tp26502728p26502728.html
Sent from the R help mailing list archive at Nabble.com.

On Nov 24, 2009, at 3:41 PM, djpren wrote:
>
> I am looking for the correct commands to do the following things:
>
> 1. I have a binomial logistic regression model and i want to test for
> overdispersion.
Under the teach a man to fish precept,   ... try:

RSiteSearch("test over dispersion binomial models")
> 2. If I do indeed have overdispersion i need to then run a quasi- 
> binomial
> model, but I'm not sure of the command.
?glm
# and follow the appropriate links
> 3. I can get the residuals of the model, but i need to then apply a  
> shapiro
> wilk test to test them. Does anyone know the command for this?

RSiteSearch("shapiro-wilks")   # not that people here recommend this  
procedure

The overall flavor of these questions is "homework", so I'm  
speculating that you may want to consult your instructors.

-- 

David Winsemius, MD
Heritage Laboratories
West Hartford, CT