Reply #137: goes like this

[RainDog]

with a PhD and an appt to teach at a U. the first level is Assistant Professor, if you get tenure, you are moved to Associate Professor. You then have another review in X amt. of years and you are then appointed to Full Professor status. Each level has salary minimums for that U. and that discipline. If you do amazing work and get nominated for a Pulitzer, etc. you can then be the "XX Professor of XX. The first is the name of someone who has endowed a dept. or U. with funds to reward work.

Just as anyone who works in a library is not a librarian (and there are all sorts of diff. kinds of librarians, too, some whose work involves tenure, just like Profs, and whose specialities do not overlap, anyone who teaches at a U. is not a professor. Someone who is a professor in one discipline is not a professor in another simply b/c of a PhD. Someone who is not a professor who teaches classes because of his/her expertise is generally called a Lecturer or a Visiting Scholar, etc.

I probably missed some of it, too. LostinVA makes a good point. No need to get upset with that. It doesn't detract from Obama's credentials because he would not teach at a well-regarded U. if he didn't have the chops.