Re: [R] urgent question about Lmer models
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 Andreywrote: > 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 126.667114.065 66.000 1.1100.271 > as.factor(treat)I-8.333114.065 66.000 -0.0730.942 > as.factor(treat)I+F1/3 -75.000114.065 66.000 -0.6580.513 > as.factor(treat)I+F2/3 18.333114.065 66.000 0.1610.873 > as.factor(treat)I+F3/3 15.917114.065 66.000 0.1400.889 > > > > 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.
[R] urgent question about Lmer models
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 126.667114.065 66.000 1.1100.271 as.factor(treat)I-8.333114.065 66.000 -0.0730.942 as.factor(treat)I+F1/3 -75.000114.065 66.000 -0.6580.513 as.factor(treat)I+F2/3 18.333114.065 66.000 0.1610.873 as.factor(treat)I+F3/3 15.917114.065 66.000 0.1400.889 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.
Re: [R] urgent question about Lmer models
Bert Gunter gmail.com> writes: > > 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 That's a good explanation, very similar to the one I posted at http://stackoverflow.com/questions/32383259/ lmertest-package-standard-errors (broken URL for Gmane). I know most people who read this message will already know this, but (to the original poster) *please don't cross-post to R lists and StackOverflow*; it causes wasted effort, as in this case. Ben Bolker __ 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.