[R] Understanding lm-based analysis of fractional factorial experiments

[Kjetil Kjernsmo]

On 03/06/2013 02:50 PM, Ben Bolker wrote:
>     Just a quick thought (sorry for removing context): what happens if
> you use sum-to-zero contrasts throughout, i.e. options(contrasts=c("contr.sum",
> "contr.poly")) ... ?

That works (except for the sign)! What would this mean?

Kjetil