Dear Sir/Madam: I have a question about computing adjusted mean using R. I am really new to this area. Suppose I have a response Y, and covariate: treat (binary), sex (binary) race (catogorical ) and age (continuous). the model: Y~treat+sex+race+age; I am asked to compute the adjusted mean of Y for treat=1. would you please tell me (in detail) how I can do this? I searched the R homepage and got some information, but not quite helpful. thanks a lot, Steven L. Lu --------------------------------- [[alternative HTML version deleted]]