[R-sig-ME] Between and within variance in a GLMM

[Renwick, A. R.]

I have a wee query regarding the variation explained by the random effect in a GLMM using lme4 package.  In the model output I was under the assumption that the value given as Std Dev is the VARIANCE BETWEEN the random factor and the VARIANCE WITHIN could be calculated using the following equation:



Variance WITHIN = ST value x Variance BETWEEN.
Therefore, Variance WITHIN = ST value x Std Dev value in model output.

However, the ST value is always equal to the Std Dev given in model output so can someone clarify how to calulate the within and between variance of the random effect.

EXAMPLE:

Generalized linear mixed model fit by the Laplace approximation
Formula: fleapresence ~ sex + width + sess + Nhat + alt + width:sess +      (1 | LocTran)
   Data: flea
  AIC  BIC logLik deviance
 1797 1863 -886.7     1773
Random effects:
 Groups  Name        Variance Std.Dev.
 LocTran (Intercept) 0.10512  0.32422
Number of obs: 1697, groups: LocTran, 14


  ..@ ST      :List of 1
  .. ..$ : num [1, 1] 0.324


Thanks
Anna

Anna Renwick
Institute of Biological & Environment Sciences
University of Aberdeen
Zoology Building
Tillydrone Avenue
Aberdeen
AB24 2TZ


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