JAMES BELLAVANCE recalls his freshman roommate at American University well. They did everything possible to make each other's lives miserable that year.

Bellavance is from a small New Hampshire town, and his roommate was probably the first Jewish person he'd met. He's neat; his roommate left piles of clothes all over their room. When Bellavance used his roommate's computer and forgot to turn it off, the roommate quickly obliged -- without saving the paper Bellavance was writing. Bellavance joined a fraternity that rejected his roommate.

Yet neither wanted to move because both had friends on the floor they lived on. But the next year, to no one's surprise, each found a new roommate.

Now a senior and a resident advisor (R.A.) helping to keep the peace for a younger crop of students, Bellavance this summer ran into his former roommate. Since they had roomed together, Bellavance had spent a semester abroad, and his roommate had transferred from AU and returned. And now . . . well, they were talking about becoming tennis partners this summer.

Starting this month, tens of thousands of young men and women will arrive at campuses to meet the roommates assigned them by the college. Mostly, freshman and transfer students are assigned roommates, since students already enrolled tend to choose their own.

"It's one of the most significant educational relationships a student can have," said Arthur Chickering, professor of educational leadership and human development at George Mason University. "A bad roommate can cause stress and distraction, but if a student is having academic trouble, a supportive roommate situation can help."

Mi-Ai Gaber, a junior at the University of Maryland, recalls anxiously waiting to meet her freshman roommate when she arrived at College Park. "I heard lots of horror stories about people hating school because of their roommates," she said.

Gaber's fears were unfounded; she and her roommate both liked to study. They kept their room clean. They weren't close friends, but they got along fine, and after that year each moved in with a friend.

The situation down the hall was another story, however. There, two young women "had horrible fights, throwing things, screaming and yelling all the time," Gaber recalled. Eventually, those two separated, to the relief of others who lived on the floor.

The process of assigning roommates varies from college to college. Some randomly match students, based on no more than the date housing applications are received. Other colleges subject students to extensive questionnaires and personality tests to come up with a compatible arrangement.

At the least, most colleges today pair smokers. Many also consider such basic information as requests for particular residence halls and roommates (if both students agree), and for co-ed or single-sex dorms. Most colleges assign roommates using these few objective factors, which is what Tom Kane, an assistant director of residence life at Memphis State University who recently completed a study of the issue, calls the business-oriented approach.

The jury is out, however, on the optimal roommate situation, and the best way for colleges to make good matches. Some housing experts maintain that colleges, being in the primary business of education, ought to purposely expose students to roommates of different cultural and socioeconomic backgrounds. Others say starting college is challenge enough, and that students should be paired with similar roommates to foster a comfortable environment.

Scott Anchors, director of residential life at the University of Maine at Orono, used personality tests to pair roommates throughout the 1980s. But he no longer uses the test because the results were mixed. "Matching people according to some criteria is important and helpful," he said, "but the key is by what criteria."

In the early 1980s, for instance, Kane had some success matching students at Chapman College in California based primarily on musical tastes. The number of requested room changes dropped from 300 the year before students were matched to only 25 requests the next year. He's hoping to use this approach next year at Memphis State.

But even matching can backfire. Until recently, Howard University paired young women from the same hometown to create a comfortable living situation. All too often, however, these women brought pre-college rivalries and emotional baggage to their new environment. "At least now we don't start with two roommates who had a grudge over a boyfriend in high school," noted William Keene, Howard's dean for residence life.

Also, colleges should match students on factors that tend not to change, advised Cheryl Beil, director of enrollment, research and retention at George Washington University. Students who went to bed by 11 p.m. at home may stay out all night once out from under their parents' wings. And because parents often help fill out the forms, just about every college ends up with smokers who didn't admit to the fact on their applications.

Housing officials and student R.A.s, who are on the front line of roommate battles, say by far the most common roommate arguments involve lifestyle, rather than personality or cultural differences: One roommate parties late, the other is an early riser; one roommate needs complete quiet to study, the other likes to listen to music; one student is neat, the other messy.

The key to resolving these differences is communication. Students must learn to "negotiate their likes and dislikes," said Patricia Lampkin, associate dean of students at the University of Virginia.

A few schools, including Howard University and Wilson College, a small women's school (200 students live on campus) in Chambersburg, Pa., have students fill out roommate contracts to address from the start such issues as visitors, quiet time for study and borrowing personal items. Other colleges informally may suggest students do this if problems arise.

Complicating the situation is the fact that many students today have never shared rooms. At an American University orientation session last year, for instance, only eight of about 70 freshmen present said they had shared a room before, noted Anne Steen, director of residential life.

Thus, many young adults have never learned the art of negotiating and compromise in their living conditions prior to college. Consider Blake Indursky from New York City, who had only shared a room at camp before starting at American University this fall. Earlier this summer, he was anxiously awaiting news of his roommate, hoping it would be "someone similar to me, so there won't be too much of an adjustment."

In addition to lifestyle differences, some students are disturbed when paired with a roommate of another race or culture or one who is homosexual. "This kind of situation is tough," said Paul Barkett, George Washington's assistant director of housing services. "The bottom line is 'Welcome to the real world,' and we encourage the students to work it out." He acknowledged, however, that if the situation gets "really bad, we will reluctantly move the student."

In fact, the University of Maryland some 20 years ago stopped sending new students information about their roommates because too many made snap judgments that they didn't want to live with the other person. "Based on a name or address, they would find out the roommate was black, white or Jewish," said Pat Mielke, resident life director. "I understand there were frequent calls from students saying, 'I just don't think we'll get along,' even before school started."

Most colleges, however, do encourage students to contact their roommates during the summer. "If not, we get a triple room with three televisions, phones, stereos and microwaves," Barkett said. "There's just not enough room."

When it comes to roommate troubles, colleges often hear from parents, too. "We hear from parents frequently, usually about a roommate having friends in the room, or making too much noise," said Bethany Marlowe, Georgetown University's residence life director. "Often they want the other student moved." Instead, she encourages parents to have their child talk to the roommate.

When problems do crop up, students often turn first to their R.A. "They tell me they can't stand the fact that their roommate comes in at 12:30 a.m. and turns the lights on, but don't tell the roommate," said Peter Konwerski, a senior and an R.A. at George Washington. Resident assistants often are trained in negotiation and mediation, but encourage students to try to work through the issues themselves.

"A lot of students are afraid of offending the other person by saying what's bothering them," said Jennifer Milligan, an R.A. at the University of Virginia. "I think most issues can be resolved, unless someone's really stepping on the other person's rights and will not change."

When all else fails, most colleges will switch roommates if space permits. "If we believe students tried and it's just not working out, we try to change them," Mielke said. "But if we believe it's a race or sexual preference issue, we recommend the student leave the residence hall."

In fact, perhaps the most surprising thing, considering how random the process can be, is how few roommate problems actually do crop up. Indeed, Marlowe said upperclass students who choose their own roommates are more likely to request room changes -- they find a great friend doesn't necessarily make a great roommate. "Some roommates learn to co-exist peacefully, some become good friends, and the others switch," she said.

Debbie Goldberg writes frequently about national education issues.