> -----Original Message----- > From: [EMAIL PROTECTED] on behalf of UKaraoz > Sent: Tue 11/18/2008 2:16 PM > To: r-help@r-project.org > Subject: [R] lmer p-values for fixed effects missing > > > I am trying to replicate the repeated measures example from Dr.Faraway's book > (Extending the linear model with R) as follows: > > data(vision) > vision$npower <- rep(1:4,14) > > mmod <-lmer(acuity~power+(1|subject)+(1|subject:eye),vision) > > > When I look at the fixed effects p-value, it is missing. Am I missing > something here? > Thanks. > > Fixed effects: > Estimate Std. Error t value > (Intercept) 112.6429 2.2348 50.40 > power6/18 0.7857 1.5400 0.51 > power6/36 -1.0000 1.5400 -0.65 > power6/60 3.2857 1.5400 2.13 >
See the discussion titled "lmer, p-values and all that" at https://stat.ethz.ch/pipermail/r-help/2006-May/094765.html and a collection of related discussions at http://wiki.r-project.org/rwiki/doku.php?id=guides:lmer-tests In a nutshell: The complexity of fully crossed mixed effects models makes degrees of freedom and other model attributes more difficult to calculate compared to fixed effects models. Research and debate is ongoing as to the best way to handle model assessment, not all classical summary statistics and associated p-values map to lmer models in a straightforward fashion. Steven McKinney Statistician Molecular Oncology and Breast Cancer Program British Columbia Cancer Research Centre email: smckinney +at+ bccrc +dot+ ca tel: 604-675-8000 x7561 BCCRC Molecular Oncology 675 West 10th Ave, Floor 4 Vancouver B.C. V5Z 1L3 Canada > > -- > View this message in context: > http://www.nabble.com/lmer-p-values-for-fixed-effects-missing-tp20569114p20569114.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > > ______________________________________________ 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.
