Hi group, I'm trying to do a Tukey test to compare the means of a factor ("treatment") with three levels in an lme model that also contains the factors "site" and "time": model = response ~ treatment * (site + time) When I enter this model in csimtest, it takes all but the main factor "treatment" as covariables, not as factors (see below). Is it possible to correctly calculate Tukey contrasts for one factor in a lme model with multiple factors using csimtest or another function in R? If so, how can I do this? Many thanks, René Eschen. # summary(simtest(response~treatment*(site+time),type="Tukey",whichf="treatment")) # Simultaneous tests: Tukey contrasts #Call: #simtest.formula(formula = response ~ treatment * (site + time), whichf = "treatment", type = "Tukey") # # Tukey contrasts for factor treatment, covariables: site +time +treatment:site + treatment:time # #Coefficients: # Estimate t value Std.Err. p raw p Bonf p adj #treatment3-treatment1 -0.655 -2.004 0.327 0.050 0.149 0.120 #treatment3-treatment2 -0.581 -1.777 0.327 0.081 0.162 0.143 #treatment2-treatment1 -0.074 -0.227 0.327 0.821 0.821 0.821 ___ drs. René Eschen CABI Bioscience Switzerland Centre 1 Rue des Grillons CH-2800 Delémont Switzerland +41 32 421 48 87 (Direct) +41 32 421 48 70 (Secretary) +41 32 421 48 71 (Fax) <http://www.unifr.ch/biol/ecology/muellerschaerer/group/eschen/eschen.html>http://www.unifr.ch/biol/ecology/muellerschaerer/group/eschen/eschen.html [[alternative HTML version deleted]]