They meet before school, during school and after school.Some are hard to get in. Others are easy. A few are more popular than the others.

They are clubs and anyone who wants to be known around school belongs to one, or two or maybe 10.

Clubs have expanded dramatically in schools throughout the Washington metropolitan area in recent years as school officials have begun to promote them in an effort to keep students interested in school.

"Without a school activity program, many students would be turned off by schools," said Tom Moran, principal of Oxon Hill Senior High School. And Frederick T. Lauriat, principal of Bethesda-Chevy Chase High School, said "I think they (clubs are absolutely critical."

The importance school officials place in clubs in evident. Clubs sponsored, encouraged, meeting on school grounds and sometimes on school time, have increased from a handful a decade ago to as many as 50 in some schools. There are the traditional ones - French club, drama club, math club and honor society. There are the not-so traditional clubs, like the computer club, Frisbee club, weight awareness club, macrame club, Bible club, aviation club, ski club, backpacking and hiking club, ecology club, karate club and host and hostess club. But all of them are part of schools' efforts to keep teenagers engaged in wholesome activities and interested in education.

"They (clubs) cover the whole spectrum," said Joann Bonner, a Prince George's County school spokesman. Some schools, like Hayfield Secondary School in Fairfax County, have in the last five years hired persons specifically to coordinate the expanded clubs.

Other schools, like Oxon Hill Senior High School, have a special activity period once every two weeks so students can learn about the school's clubs and perhaps be persuaded to join.

"There is an extracurricular program for every student in the school," said Frank Tracy, principal of High Point High School.

Lisa Pettipas, a senior, is a member of the W. T. Woodson High School Precisionettes in Fairfax County.

"It keeps me from getting bored," she said after an 11 a.m. practice in the school gymnasium recently. She was among 34 girls who belong to the Precisionettes and were using their lunch hour to prepare for an upcoming performance.

To the tune of marching music, the girls paraded on the gymnasium floor. In synchronized movements, like those of a tin soldier, the girls extended their right arms straight upward, then their left arms, then extended their arms from side-to-side, and finally dropped their arms to their sides - all while they continuingly smiled and marched.

"You get to know a lot of people," said Susan Frisbee, a junior of the drill team, which has become one of the most popular groups for girls at the school.

"It gives you a lot of self-confidence," said Becky Pratt, another senior on the team. "I think it promotes school spirit."

The popularity of the group creates stiff competition for the 34 positions. Last spring, 180 girls tried out for the team. The tryouts lasted two weeks, according to the group's sponsor, Diane McCaulay, who is affectionately called "Mom" by the students.

While the Precisionettes meet during the lunch hour, after school and on weekends, the Key Club, which is a service organization at the school, meets only once a week at night.

The Key Club is not as competitive as the drill team in that the club generally accepts anyone who shows up for a meeting. "You make a lot of friends and it keeps me busy," Bob Wagner said of the Key Club, which he heads.

The karate club at High Point High School in Beltsville is among the fairly new clubs to arrive at schools in recent months. Its creation is a familiar and simple story repeated throughout area schools.

One day last year, a student asked the school principal, Frank Tracy, if he could form a karate club. Tracy instructed the student that he had to find a sponsor for the club.

After three weeks of hunting for a sponsor, the student asked Tracy to sponsor the group. He did. About 15 students meet once a week to learn and practice karate exercises.

The karate club is the first school club that Roger Holmes has joined since he enrolled at the school four years ago. "I wanted to get the experience," he said. "I enjoy getting in shape and staying limber," said the senior.

"The specification for a club is very simple," said Barbara Small, assistant director of student activities at Hayfield Secondary School. "Find a sponsor, have a room to meet and get enough students to participate."

Most clubs raise their own money by giving dances and raffles.

"This is what makes the school," said Bill Caudill, athletic director and director of student activities at Woodson High School in Fairfax County."If you get a kid involved in something in the school, you don't have many problems."