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

T. Florian Jaeger tiflo at csli.stanford.edu
Tue Nov 9 19:14:31 CET 2010


Hi Jarrod and Doug,

thanks for the straightforward answers and for the suggestions of an
alternative. This is very helpful.

florian

On Tue, Nov 9, 2010 at 7:37 AM, Jarrod Hadfield <j.hadfield at ed.ac.uk> wrote:
> 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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>>
>
>
> --
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
>
>




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