Hi, when I fit a linear model as
lm(o ~ y + s - 1, contrasts=list(s=("contr.sum")),na.action=na.exclude) should then the effects of factor s sum up to zero? I my case they don't. Where is the misunderstanding or the mistake? Thanks, joerg ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.