ROBERT ROSENBLUM, curator and critic, lectures on "Inside/Out: Picasso vs. Bouguereau in 1900" at 6 p.m. on Thursday, Dec. 7, in the Carpenter Center auditorium. I'll be there cheerleading for B to the O to the U to the G to the U to the E to the R to the E to the A to the U.

When you try to put a performance, a happening, a tableau vivant in a museum, what do you get? Very little; the thing is over and done with and the museum-goer mulls over the leftovers, the photographs and documents, like a detective looking over a reopened file. It's tough to present artists who work in the medium of willful impermanence: pity the curators. And hear what three such artists-ALLAN KAPROW, inventor of the capital-H Happening, PAUL McCARTHY, the most scatological performance artist now working, and VANESSA BEECROFT, best known for her work with large roomfuls of naked girls-have to say about the exhibition of the traces of their work in a discussion at 2 p.m. on Saturday, Dec. 9, in MIT Room 10-250, 77 Mass. Ave. It's free; just show up early to get a seat.

Performance artist MILAN KOHOUT talks about his work with the Roma people (Gypsies) of the Czech Republic at 7 p.m. on Monday, Dec. 11, at Mobius, 354 Congress St., Boston. For more information, call 542-7416.