Hi, I have trouble to figure out how the df is derived in LME. Here is my model, lme(y~x+log(den)+sex+dep,data=lwd,random= list(group=~x)) Number of total samples (N) is 3237 number of groups (J) is 26 number of level-1 variables (Q1) is 3, i.e., x, log(den) and sex number of level-2 variables (Q2) is 1, i.e., dep x and den are continuous variable sex is associated with individual samples and has 2 levels dep is associated with group has 4 levels: depD15, depD27, and depD35, and depD35. I got the results: Fixed effects: y ~ x + log(den) + sex + dep Value Std.Error DF t-value p-value (Intercept) -11.29271 0.1681915 3206 -67.14200 <.0001 x 3.05937 0.0367970 3206 83.14182 <.0001 log(den) 0.00898 0.0022357 3206 4.01732 0.0001 sex 0.01980 0.0057675 3206 3.43216 0.0006 depD27 -0.01505 0.0560142 3206 -0.26872 0.7882 depD35 -0.06102 0.0548647 3206 -1.11227 0.2661 depD50 -0.29123 0.0567132 24 -5.13511 <.0001 Are these coefficients are the level-2, and thus, DF for testing dep's should be (J-Q2_1=26-1-1=24). Why I get the number 3206, especially for depD27 depD35 and depD50. Thanks Han Han-Lin.Lai at noaa.gov -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._