I cannot seem to get the aic or extractaic call to work with multinomial logistic regression models. Here is what I am doing: library('Design') lrm1<-lrm(r1~p1) #where p1 is multinomial and r1 is binomial library('MASS') aic(lrm1) Error in if (fam %in% c("gaussian", "Gamma", "inverse.gaussian")) p <- p + : argument is of length zero also tried extract.aic and others to no avail I was able to get aic to give what looked to be reasonable results with nnet functions like multinom -- am i missing basic statistics knowledge here or is there a problem with my code? thanks _________________________________________________________________ Intro*Terms