Dear Dr. Boli: What’s up with all these different kinds of professors? There are professors and tenured professors and associate professors and adjunct professors and visiting professors and professors emerituses and it just makes my head swim. What do all the titles mean? —Sincerely, A Freshman at Duck Hollow University Wondering Whether It’s Worth While Showing Up for Classes.

Dear Sir or Madam: It is not always easy to distinguish the various kinds of professorships, but it is often useful in one’s college career to be able to do so, mostly for gossip purposes.

Professors are people who teach in universities. They are nearly extinct.

Tenured professors sit in named chairs endowed by wealthy donors and cannot be dislodged by any means, unless they make an offhand remark that offends the donor, in which case they are blown up with dynamite.

Associate professors are employees who are paid a small salary to be willing and available to associate with the tenured professors, who would otherwise have no friends, because they all hate each other.

Assistant professors help the tenured professors leave their chairs and make their way to the bathroom when it becomes necessary.

Adjunct professors are devices attached to a tenured professor to boost the professor’s productivity. It is not known how effective they are, but careful measurements will be taken as soon as a tenured professor produces something.

Research professors are professors who avoid students even more successfully than other kinds of professors.

Visiting professors are the older people you occasionally see wandering around campus pointing at things.

A professor emeritus is a professor of one sort or another who is no longer working but is still listed among the faculty. At many universities, all the professors are professors emeritus.