[R] Kenward-Roger correction in lme

[Ben Bolker]

stian <at> mail.rockefeller.edu <stian <at> mail.rockefeller.edu> writes:
> Hi,I am wondering how to conduct Kenward-Roger correction in 
> the linear mixed model using R. Any idea?
> 
> Thanks a lot,
> 
> Suyan

  Not really possible, I'm afraid.  Having already invested a huge
amount of time in making lme4 available (and this is the cutting-edge
version of linear mixed models for R), Doug Bates has declined to
spend effort implementing K-R because (1) he's not convinced of the
appropriateness of adjusting F-distribution degrees of freedom in
this way, (2) he doesn't think that the K-R algorithm will be
feasible for the sorts of large-data problems he's interested in,
(3) [can't find the reference] he finds the correspondence between
K-R's notation and his difficult.

  This should probably go on an FAQ list somewhere:

By the way,  RSiteSearch("Kenward-Roger") would have
yielded some information ...

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/81969.html
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/49633.html

  For further information, please see the r-sig-mixed archives.

  cheers
    Ben Bolker