Dear all, I have a question about the regression tree function in R. After applying the tree() function for my data, I found out the "n" value in the output (the (weighted) number of cases reaching that node) is always less than my total sample size. My guess is becasue some of the cases are not useful to predict the node. I am not very confidence with my guess and I do expect to know some "formal" explaination. Thank you very much! Cheers, Jessie