Re: [R] mixed models: correlation between fixed and random effects??

From: Spencer Graves <spencer.graves_at_pdf.com>
Date: Sun 15 Oct 2006 - 02:04:32 GMT

      I suspect you've observed an outcome that occurs once out of every 2^4 = 16 times. Have you tried Monte Carlo, e.g., using 'simulate.lme' in library(nlme) or 'mcmcsamp' in library(lme4)?

      Hope this helps. 
      Spencer Graves

Bruno L. Giordano wrote:
> Hello,
> I built 4 mixed models using different data sets and standardized variables
> as predictors.
>
> In all the models each of the fixed effects has an associated random effect
> (same predictor).
>
> What I find is that fixed effects with larger (absolute) standardized
> parameter estimates have also a higher estimate of the related random
> effect. In other words, the higher the average of the absolute value of the
> BLUPs for a given standardized parameter, the higher its variance.
>
> Is this a common situation or I am missing some additional normalization
> factor necessary to compare the different random effects?
>
> Thanks a lot,
> Bruno
>
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Bruno L. Giordano, Ph.D.
> CIRMMT
> Schulich School of Music, McGill University
> 555 Sherbrooke Street West
> Montréal, QC H3A 1E3
> Canada
> http://www.music.mcgill.ca/~bruno/
>
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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. Received on Sun Oct 15 12:18:23 2006

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