HOME MOVIES -- At the Key.

One characteristic of "sophomoric humor," which is not always related to age or enrollment, is that it's crude and unstable. That just tells you what kind of humor it is -- not whether it's successful or not -- and some of it can be quite funny.

But the "sophomoric" quality that has less chance with a wider audience is satire that's not based on any original experience or observation of life, but rather takes already-established types from mass comedy's stock figures and then redoes them with additional crudity.

This is the approach in "Home Movies," a newly released film that Brian De Palma made a couple of years ago at Sarah Lawrence College's film workshop, where he was teaching film. It is, of course, about a superstar professor (played by Kirk Douglas) teaching a course in film. Or rather, it is, as he calls it, a course in "Star Therapy," the purpose being to make each student feel "like the star of your own life, and not an extra," rather than to teach them the techniques of filmmaking.

A nymphomaniac, a neo-Nazi male chauvinist, a whiney, suicidal mother and a lascivious doctor father, complete with giggling Swedish nurse, are the characters of the film-within-a-film, and a dreary lot they are, even filthied up for the occasion.

De Palma has gone on to success, and one hopes that the Sarah Lawrence students who worked on this project learned from it. But one lesson they all missed is that no one wants to see anybody else's home movies.