[R-sig-ME] quasi-binomial family in lme4

[Jarrod Hadfield]

Dear Doug,

That would be very welcome. It might be nice for lmer to fit a  
residual term if quasi models are specified, since this now seems to  
be working?

Cheers,

Jarrod




On 9 Nov 2010, at 15:26, Douglas Bates wrote:

> On Tue, Nov 9, 2010 at 9:02 AM, Jarrod Hadfield  
> <j.hadfield at ed.ac.uk> wrote:
>> Hi Florian,
>>
>> This comes up regularly and the list (nearly) always stays silent.  
>> As far as
>> I am aware quasi models in lmer do not, and never have, given  
>> sensible
>> results. To model over-dispersion you can try fitting an  
>> observation-level
>> random effect. For example:
>>
>> data$resid<-as.factor(1:dim(data)[1])
>>
>> and fitting (1|resid) in the model formula.
>>
>> This year  I have reviewed four papers that have used quasi models  
>> in lmer,
>> and its no fun to tell the authors that their results may not be  
>> meaningful.
>> To paraphrase an earlier post, why are they there if they do not  
>> work - it's
>> irresponsible?
>
> I agree.  I should have removed them from lme4 long ago if I suspected
> that the results were not correct.
>
> I will do so (once I figure out how to forbid them).
>
>> On 8 Nov 2010, at 03:30, T. Florian Jaeger wrote:
>>
>>> Hi,
>>> I am analyzing some data that seems to require a quasibinomial  
>>> model,
>>> but the model returns incredibly small standard errors (and
>>> correspondingly inflated t-values) that do not seem to be justified
>>> given my data.
>>> I've been reading (I think) all available posts on problems with the
>>> quasi-binomial family in lme4. But I can't judge from the posts
>>> whether all issues with the  quasi-binomial models in lme4 are  
>>> assumed
>>> to be resolved. So, I am wondering, are there any known issues with
>>> quasi-binomial models in lme4?
>>>
>>> I am using
>>>
>>> Package:            lme4
>>> Version:            0.999375-35
>>> Date:               2010-08-18
>>>
>>> in environment:
>>>               _
>>> platform       i386-pc-mingw32
>>> arch           i386
>>> os             mingw32
>>> system         i386, mingw32
>>> status
>>> major          2
>>> minor          11.1
>>> year           2010
>>> month          05
>>> day            31
>>> svn rev        52157
>>> language       R
>>> version.string R version 2.11.1 (2010-05-31)
>>>
>>> cheers,
>>> Florian
>>>
>>> _______________________________________________
>>> R-sig-mixed-models at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
>>>
>>
>>
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>


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Scotland, with registration number SC005336.