[R-sig-ME] Fwd: same old question - lme4 and p-values

Kevin E. Thorpe kevin.thorpe at utoronto.ca
Fri Apr 11 15:10:41 CEST 2008

This has been a very interesting thread.  However, I'm still
wrestling with what to do for a fixed-effect that has more than
one degree of freedom.

In the data I'm analyzing, I have three groups to compare.

So, I can get CIs for the two parameters, but that is a bit
problematic for assessing an overall difference.

Is it valid to do the following?  Estimate the parameters using both
ML and REML.  If the estimates show good agreement, is that sufficient
evidence to conclude the ML procedure is converging and that I can
use a likelihood ratio test for the fixed effect?

Thanks for your comments.


Kevin E. Thorpe
Biostatistician/Trialist, Knowledge Translation Program
Assistant Professor, Department of Public Health Sciences
Faculty of Medicine, University of Toronto
email: kevin.thorpe at utoronto.ca  Tel: 416.864.5776  Fax: 416.864.6057

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