You need to consult a local statistical expert or post on a statistics list like stats.stackexchange.com . This is a statistical question not an R question.
The answer is: Because the design is balanced and the treatment error is obtained from the (within site) rsd, but you will probably need more explanation than this. BTW, if you haven't already done so, try making some informative trellised plots to understand what is going on. Formal statistical analysis alone can be very misleading. Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Thu, Sep 3, 2015 at 8:57 AM, Aline Andrey <aline.andr...@gmail.com> wrote: > Dear r-help, > > I have a question about the std error of a lmer model with library > (LmerTest). > > I have 12 sites with 6 treatments over each site. I measured some response > variable (biomass_of_insects) (with a gaussian distribution). > > I did : > library (LmerTest) > model<- lmer((biomass_of_insects) ~ as.factor(treatments) + (1 | sites)) > > However, the response of the model show always the same std error (see > below): > > Fixed effects: > Estimate Std. Error df t value Pr(>|t|) > (Intercept) 501.333 80.656 66.000 6.216 3.91e-08 *** > as.factor(treat)F 126.667 114.065 66.000 1.110 0.271 > as.factor(treat)I -8.333 114.065 66.000 -0.073 0.942 > as.factor(treat)I+F1/3 -75.000 114.065 66.000 -0.658 0.513 > as.factor(treat)I+F2/3 18.333 114.065 66.000 0.161 0.873 > as.factor(treat)I+F3/3 15.917 114.065 66.000 0.140 0.889 > > > > Do you know why std.error is always the same ? > > Thank you very much, > > Aline > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
