[R-sig-ME] submitted for list review: ezBuildME()

[Hadley Wickham]

> - a test of a 2-way interaction compares a model containing the 2-way
> interaction plus the main effects of all predictors plus the random
> effect against a model with just the main effects and the random
> effect. eg:
>    dv ~ v1:v2 + v1 + v2 + v3 + (1|wid)
>        versus
>    dv ~ v1 + v2 + v3 + (1|wid)
>
> - a test of a 3-way interaction compares a model containing the 3-way
> interaction plus all 2-way interactions plus all main effects plus the
> random effect against a model with all 2-way effects, all main
> effects, and the random effect. eg:
>    dv ~ v1:v2:v3 + v1:v2 + v1:v3 + v2:v3 + v1 + v2 + v3 + (1|wid)
>        versus
>    dv ~  v1:v2 + v1:v3 + v2:v3 + v1 + v2 + v3 + (1|wid)

It's a small point, but this comparison is easier to understand if expressed as:

dv ~ (v1 + v2 + v3) ^ 3 + (1 | wid)
vs
dv ~ (v1 + v2 + v3) ^ 2 + (1 | wid)

Hadley

-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/