During 3 1/2 years at Oxon Hill High School, 16-year-old Reisha Raney has developed a simple code of conduct for avoiding fights in school. Whenever someone insults her, she ignores them and walks away.

So far, her refusal to fight has served her well, Raney said, but it also has had a cost. Turning the other cheek has kept her from being punched or suspended, but it encourages mean stares and unflattering rumors designed to goad her into responding, she said.

"It's for popularity. They think if they fight and everyone hears about it, no one will mess with you again," Raney said.

What enables Raney and others like her to resist violent confrontations while others cannot is something education officials in Prince George's County have become increasingly interested in as they combat a dramatic increase in the number of assaults on school grounds.

During the 1989-90 school year, 468 Prince George's students, teachers, administrators and other adults were assaulted in school, an increase of 44 percent from the year before and the highest number in six years, according to the latest report on crime in county schools.

School system figures show that the perpetrators were both younger and more violent than in previous years. The 214 incidents at elementary and middle schools accounted for more than two-thirds of the increase in assaults. The number of serious injuries resulting from assaults was up by 19 percent, with 10 victims ending up in the hospital and 94 others requiring treatment by doctors.

At the same time, the 77 assaults on teachers last year represent the largest number since the school system began monitoring such behavior eight years ago. In elementary schools, there were 18 attacks on teachers last year, an increase of 16 from 1988-89.

School officials say they are alarmed by the increase, but that they do not regard it as an epidemic. They said the number of assaults is relatively small, considering with Prince George's student population of 107,000, and that many students complete their educations without a scuffle.

"There is a lot of bumping and pushing that goes on that is done with no intent to be an assault, but we still treat it as one," said Peter Blauvelt, director of school security in Prince George's.

The number of students suspended or expelled for carrying weapons -- 122 -- was unchanged from the previous year. Blauvelt said few of the guns, knives or bats confiscated were used to commit crimes.

By contrast, weapons played large roles in two recent incidents involving students in the District, where a senior at Eastern High School was stabbed in a hallway during an argument over a bag of corn chips and five young children were shot in the Shaw neighborhood on their way home from school.

Nevertheless, Prince George's officials acknowledge having been surprised by the rise in assaults during a year in which the school board adopted a policy making participation in a "group fight" -- even watching one -- grounds for expulsion.

Trying to explain the trend, educators have looked beyond schools to the communities in which students live. Peer pressure, poor self-images, neighborhood crime and a popular culture that celebrates violence all play a part, they agree.

"What concerns us is that some kids seem to think a knife or gun is a necessary part of their wardrobe, not because of what goes on in school, but {because of} what might happen when they go to the mall or a party," Blauvelt said.

At Oxon Hill, which tied with Suitland High School last year for a systemwide high of 28 reported assaults, students interviewed said the vast majority of serious fights start with what they described as "stupid stuff," such as an unkind remark, a misdirected flirtation or lingering rivalries.

Though some students wear their brawling records like badges of honor, even those who are hesitant to get involved in fights might find it difficult to back away once they think their pride has been challenged and a crowd gathers to cheer the fireworks, students said.

"If you are scared, then all the people mess with you," said Rhonda Banks, 17, a senior who said she was suspended twice last year -- one time for 1 1/2 months -- for fighting in school. "If you act the way they act toward you, they leave you alone."

Milton Steinbaum, Oxon Hill's principal, said some students provoke fights in school rather than outside because they are guaranteed an audience.

"Sometimes kids will get in a fight where they know an administrator or teacher is around because they know they will break it up . . . . They can still look cool and know things will not get too out of hand," Steinbaum said.

Steinbaum's approach to curb assaults has been to make examples of wayward students by announcing suspensions over his school's public address system.

The staff at Charles Carroll Middle School in New Carrollton has taken a more scholarly approach. In September, social studies teachers began giving students a daily lesson in "conflict resolution" from a curriculum developed specifically to reduce suspensions.

The goal of the lessons, which include segments on multicultural awareness, teamwork, self-esteem, anger and values, is to give students the skills and self-confidence to resolve disputes peacefully before they reach the heated atmosphere of high school, said teacher William Ryan, who was chairman of the panel that developed the material.

"Society as a whole just seems unable to deal with conflicts without inflicting harm, so it's not surprising that the only avenue many kids know is to go out and smack someone," said Herman Schiemer, Charles Carroll's principal. "We are trying to give them alternatives."