[R] anova(mymodel.lme, type = "marginal")

[Federico Calboli]

Dear All,

recently, while setting me on the straight and narrow about linear
contrasts for a linear mixed effect model, Prof Ripley pointed out that my
interpertation of the call 

anova(mymodel.lme) 

was not correct, because I was meant to add 

type = "marginal", as in anova(mymodel.lme, type = "marginal")

I tried to look deeper in the issue, asking people, checking on the R-list
archives and googling around, but the best I could find was another old
post reiterating that the anova call for fixed terms in a mixed model
requires *type = "marginal"*. I also checked MASS IV and Pinheiro & Bates,
but I am not sure how much I got from my read.

As I am not a statistician, I'd simply like to ask whether is this the
*standard* way of generation an anova table for a mixed effect model, or,
if it is not, what are the general rules underlying the application of a
marginal approach for a mixed model effect.

Regards,
Federico Calboli




=========================

Federico C.F. Calboli

Department of Biology
University College London
Room 327
Darwin Building
Gower Street
London
WClE 6BT

Tel: (+44) 020 7679 4395 
Fax (+44) 020 7679 7096
f.calboli at ucl.ac.uk