[R] lmer with nested/nonnested groupings?
spencer.graves at pdf.com
Mon Jan 16 00:01:43 CET 2006
RSiteSearch("lmer nested") produced 85 hits, the first of which looks
to me like it would answer your question
(http://finzi.psych.upenn.edu/R/Rhelp02a/archive/61571.html): Have you
tried replacing "state" with "region:state" something like the following:
> lmer (y ~ black*female + (1 | region:state) + (1 | region) + (1 |
age) + (1 | edu) + (1 | age.edu), family=binomial(link="logit"))
But please read the earlier post, as makes cites other documents,
e.g., the "MlmSoftRev" vignette, and contains useful comments from Doug
Bates, among others.
hope this helps.
Andrew Gelman wrote:
> I'm trying to figure out how to use lmer to fit models with factors that
> have some nesting and some non-nested groupings. For example, in this
> we have a logistic regression of survey respondents' political
> preferences (1=Republican, 0=Democrat), regressing on sex, ethnicity,
> state (51 states within 5 regions), 4 age categories, and 4 education
> categories. I'd like to include states (nested within regions), and
> also age, education, and age x education. (That is, 5 batches of
> varying coefs: 50 states, 5 regions, 4 age categories, 4 education
> categories, and 16 age x education categories.) The age x education
> factor is kinda tricky because it's connected both to age and to education.
> I'm thinking of a model like this:
> lmer (y ~ black*female + (1 | state) + (1 | region) + (1 | age) + (1 |
> edu) + (1 | age.edu), family=binomial(link="logit"))
> (Here, I'm thinking of age.edu as a variable with 16 levels.)
> Anyway, it blows up when i try to put in these nested things. I read
> Doug Bates's article in R-news and there seems to be a way of doing
> nested groupings (unfortunately, I can't quite figure out how to do it),
> but I don't see any references to situations such as age, edu, and age*edu .
> For the article, we used Bugs, which is fine, but I'd like to see how
> far I can take it using lmer. I could kludge it by, for example,
> including age, edu, and region as unmodeled factors:
> lmer (y ~ black*female + (1 | state) + factor(region) + factor(age) +
> factor(edu) + (1 | age.edu), family=binomial(link="logit"))
> but I'd like to do the full multilevel version.
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