The day began well for Alicia Kuhles, but the 15-year-old student's mood soured swiftly and a Ping-Pong game was her undoing.

Angered because she thought her opponent was cheating, the sweet-faced girl deliberately spiked the ball against a far wall -- and won herself a strong demerit that wiped out her good grades for the rest of the day.

The infraction would be a minor one at most other schools, but Alicia is an eighth grader at the Elm Street School in Frederick, Md., an unusual school in which every misbehavior is taken seriously. The crumbling brick building topped by a cupola houses a Frederick County program for troubled adolescents with behavior problems so severe they disrupt any classroom they attend. Some have police records. One once waved a gun in the cafeteria.

The Elm Street program, which combines close supervision with strong discipline, has been designated a model by Maryland's Department of Education. Tonight the program may spread to Fairfax County, where the School Board is scheduled to vote on implementing a pilot program for seventh and eighth graders that is substantially based on the Elm Street model.

In the program, there is one teacher, counselor or aide for every five students. The students are graded on a point system every 15 minutes in an effort to reinforce good behavior. After moving through five levels of increasing privileges, they can eventually graduate back to their regular schools. There is extensive counseling for the family, as well.

"When I first came here, I was a brat," said Kuhles, admitting she still has a long way to go after a year at Elm Street. "This school's helped me a lot. Things I could get away with in regular school, I could never get away with here."

Fairfax County School Board Chairman Mary E. Collier said the program would serve students who are not qualified for special education programs but who cannot operate in a regular school environment. Some, she said, might drop out or turn to crime.

"We're hoping that by using a very, very structured intervention program they'll be able to turn themselves around," she said. Removing them from regular classrooms will allow teachers -- who often have to spend much of the day coping with one troublesome teen-ager -- to spend more time with other students, she said.

The Fairfax County program would be housed at the former Bryant Intermediate School in the Groveton section, with 25 students and a staff of eight. A county task force studied the program and recommended it in a 1984 report.

Collier said she has heard that some families who live near the proposed school have expressed concerns about possible crime, but she said the students would be "extremely well supervised" and therefore not dangerous.

The Frederick program, which began in 1976 and moved to Elm Street in 1982, now has 36 disruptive special education students, including Kuhles, and 45 troubled regular students. The vast majority are boys and many of the students are from low-income families.

Although some of the students have problems with their studies, that is not always the case, and school staff members speak proudly of the youth who attended math classes for gifted high school students in a Johns Hopkins University night program.

It is possible to get through Elm Street's five levels in nine weeks, but most students take seven to eight months, according to Estes Lockhart, who founded the program and now is in charge of psychological services for the county schools.

"All of these [students] are basically normal kids," Elm Street Principal Judy Curtis said. "They're just under stress and they react by behaving obnoxiously. The idea is to confront them about their behavior, support them, and teach them how to deal with it."

Matthew Kline is close to transferring from Elm Street. His grades, once all Fs, now are "fair," he said. Kline is on level four. At level five, students are allowed to walk around the school by themselves, without a teacher escort. Kline, a 15-year-old eighth grader, has four times hoisted himself up to that last level in his 15 months at Elm Street, only to fall back because of bad behavior.

Asked whether he wants to return to his former school, Kline said, "In a way, yes. In a way, no. I'm having a lot of success."

That, said Curtis, is one of Elm Street's potential problems, and one reason the school does not try to be a perfect place.

"If we made it too great, they wouldn't want to leave," she said. "And our objective is to get them back to their mainstream school."