Dear all,

I have been having some trouble with the new version of the lmerTest
package (or the current one used in R 3.0.2 instead of 2.14.1). A
comparison of the outputs can be found here:
http://rpubs.com/charlotte_recapet/11269

1) As illustrated in the first part of the script, the new version does not
perform the same elimination process as the old one: different elimination
and rank and statistics

2) Then, in the new version, the anova function does not give the same
statistic and denominator degrees of freedom as the step function for the
first eliminated effect.

3) Eventually, on a smaller dataset, when eliminating one of the two random
effects (variance=0), the step function considers the model as
fixed-effects only and does not do any effects selection. In the old
version, with the same data, I got a selection.

 I also find strange that the test for the random effects in the old
version gave the same stats for both effects (but no more in the new
version).

Do you have any idea to explain the discrepancy of the outputs between R
versions, and even of the results of different functions of the package in
the same version of R?

Thanks a lot for your help!

	[[alternative HTML version deleted]]

