Dear all, I am struggling with a problem which I have been reading on the forums about and it did not seem to me that there is a precise answer to my question. However, I still hope there is one. I am working with http://timss.bc.edu/ PIRLS data and trying to conduct multilevel analysis. There are different weights for each level of analysis in the PIRLS dataset (e.g. there is a school weight, class weight, student weight). Is there a function in R which would let me use different weights for different levels of my model? If yes, which package contains it? I would be very grateful for any help! -- View this message in context: http://r.789695.n4.nabble.com/sampling-weights-for-multilevel-models-tp4632947.html Sent from the R help mailing list archive at Nabble.com.
Hello,
The link you've posted is to a page that does NOT have a dataset, it has
links to other pages. The proper way of posting a data example would be
# paste the output of this in a post
dput(head(yourdata, 20)) # or 30
Now, if I understand your question, function sample() does have a
weights argument, 'prob'. (Package base.) See
help("sample")
Hope this helps,
Rui Barradas
Em 10-06-2012 20:00, Tamara escreveu:> Dear all,
>
> I am struggling with a problem which I have been reading on the forums
about
> and it did not seem to me that there is a precise answer to my question.
> However, I still hope there is one.
>
> I am working with http://timss.bc.edu/ PIRLS data and trying to conduct
> multilevel analysis. There are different weights for each level of analysis
> in the PIRLS dataset (e.g. there is a school weight, class weight, student
> weight).
> Is there a function in R which would let me use different weights for
> different levels of my model?
> If yes, which package contains it?
>
> I would be very grateful for any help!
>
>
>
>
>
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/sampling-weights-for-multilevel-models-tp4632947.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
On Mon, Jun 11, 2012 at 7:00 AM, Tamara <petrova.toma at gmail.com> wrote:> Dear all, > > I am struggling with a problem which I have been reading on the forums about > and it did not seem to me that there is a precise answer to my question. > However, I still hope there is one. > > I am working with ?http://timss.bc.edu/ PIRLS ? data and trying to conduct > multilevel analysis. There are different weights for each level of analysis > in the PIRLS dataset (e.g. ?there is a school weight, class weight, student > weight). > Is there a function in R which would let me use different weights for > different levels of my model? > If yes, which package contains it? >As far as I know there is no function that does what you want. In particular, lme() and lmer() don't work correctly with sampling weights. It does depend on why you want a multilevel model. If you are primarily interested in the mean model and the variance components are just needed to get appropriate standard errors, then you can use the svyglm() function in the survey package to fit a linear regression with appropriate standard errors. On the other hand, if you are interested in estimating the variance components for their own sake, you need some other software. I do have longer-term plans to add multilevel modelling capabilities to the survey package, but it's harder than it may appear. -thomas -- Thomas Lumley Professor of Biostatistics University of Auckland