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

[Bruno L. Giordano]

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/