With three co-operative dormitories housing 54 students, Harvard strikes the middle ground among the Ivy League schools whose cooperative arrangements range from informal off-campus groups at Yale to a more extensive plan at Cornell.

"There are some things scattered about but there is no formally insitutionalized cooperative housing," Yale's housing office spokesman says.

At Brown there is about the same interest in cooperative housing as at Harvard. The Brown Association for Cooperative Housing, an independent student organiation, has 55 students living in three co-op houses. Unlike Harvard, the Brown co-ops are privately owned and both the room and the board are cheaper than living in regular dorms, says Elissa Sheridan, a junior and resident of one of the Brown co-ops. At Harvard, a co-op room costs the same as a room in one of the Houses, but the savings comes in the board.

Cornell offers a co-op program more extensive than any of the other Ivy League schools, with the 10 university-owned co-ops housing about 200 students, according to Bill Kaminski, a housing official at Cornell. Room and board at the co-ops are about 25 percent less expensive than the dorms, Kaminski says, explaining that the co-ops are a popular option: "We rarely have trouble filling them."

At MIT there is only one formal cooperative house--called Student House--which is owned and operated by its residents. The residence provides housing for financially needy students who must be approved by MIT's financial aid office. The 30 students who live in the house pay about half of what other students are charged for room and board, according to Associate Dean for Student Affairs Bob Sherwood.

Outside of the Ivies, it is not unusual for some schools to house thousands of students in cooperatives. At the University of California at Berkeley, for example, the co-op lifestyle is flourishing, according to Craig Reynolds, a spokesman for the University Students' Cooperative Association, which is celebrating its 50th anniversary this year.

Oberlin College in Ohio has a relatively substantial cooperative housing system in which the actual buildings are owned by the college but the maintenance is run by an independent student group. According to housing and dining coordinator Anne Ludlow, about 150 students live in the co-ops and pay about one-third of the board which students in regular dorms are charged. In return the students spend four hours a week doing housework in the co-ops as well as ordering and preparing food. Ludlow attributes the popularity of Oberlin's co-ops--which are about 30 years old--to the opportunity they offer for students to form "close relationships in a smaller community."