ok... the model now runs properly (say, without errors). Now about the result. These are the averages per treatments
tapply(VecesArbolCo.VecesCo.C1,T2,mean) a b c d 0.49 0.56 0.45 0.58 I run this very simple model > summary(model1<-lmer(cbind(VisitsExpTree,TotalVisits-VisitsExpTree)~ > treatment +(1|Individual), family=binomial, data=r)) Generalized linear mixed model fit by the Laplace approximation Formula: cbind(VisitsExpTree,TotalVisits-VisitsExpTree)~ treatment +(1|Individual) Data: r AIC BIC logLik deviance 242.3 255.9 -116.2 232.3 Random effects: Groups Name Variance Std.Dev. Individuo (Intercept) 0.14075 0.37517 Number of obs: 112, groups: Individuo, 37 Fixed effects: Estimate Std. Error z value Pr(>|z|) (Intercept) 0.37228 0.19031 1.9562 0.05044 . treatmentb 0.03367 0.24520 0.1373 0.89079 treatmentc -0.60606 0.23330 -2.5978 0.00938 ** treatmentd -0.25504 0.22790 -1.1191 0.26311 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Correlation of Fixed Effects: (Intr) T2b T2c T2b -0.675 T2c -0.697 0.543 T2d -0.720 0.544 0.581 wouldnt we expect the intercept to be roughtly the mean of treatment a? and thus the estimate of treatmentb to be +0.07, c: -0.04 and d: +0.09 roughly? Is this model just completely not estimating well, or are the estimates not the 'real values'. I tried to get teh predict function to give me the 4 predicted values based on the model, but i havent succeeded in doing so. maybe someone can help me on that one too (predict(model1,type="response") doesnt work) thnx -- View this message in context: http://www.nabble.com/Mixed-effects-model-with-binomial-errors----problem-tp19413327p19436083.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.