Every weekend, Jennifer Jones, 16, a former student at the Duke Ellington School of the Arts, travels to the Arena Stage Theater in Southwest. But she's not one of the actors and she's not part of the audience.

Rather, she's a volunteer who works as an usher and poster seller.

"I'm trying to show society that there are teen-agers that will volunteer and help the community," said Jones, who started working in September to stay in touch with the theater after she transferred to an academic high school.

Jones, like 250 other young people, found her job through Young Volunteers in Action (YVA), a project started in November 1983 to introduce 14- to 22-year-olds to community service and to meet the growing demand for volunteers.

"Students tend to be harder to place," said Debbie Cotton, director of the District's YVA program.

"Volunteer coordinators are wary of [young people's] reliability and sense of commitment" because of their youth, she said.

Jones added, "People see . . . [how old I am] and they say, 'Can we trust you with money and such things?' "

Cotton, who during the past year has obtained signed contracts from more than 50 community organizations agreeing to work with youth volunteers, said that once a young volunteer has broken the ice at an agency, volunteer coordinators are usually eager for more.

The young volunteers work in a variety of jobs, including companions for the elderly, medical assistants, producers for children's theaters and office workers.

About 70 percent of the youthful volunteers are from the city and 30 percent from the suburbs, Cotton said.

The volunteers usually work at least 20 hours a week, and most put in their hours after school.

Young people want to become volunteers because they are too old for traditional camp or after-school activities but are not old enough to get paying jobs, "although they are very competent," Cotton said.

Many of the YVA participants want to help others less fortunate than themselves and request the "hard-core" volunteer jobs at social service organizations, such as shelters for the homeless or crisis hot lines, Cotton said.

Others are career-conscious and volunteer in order to explore a career or to gain experience to bolster a resume.

When Dimitri Christakis, 20, talks about his work as a volunteer at the Montgomery County Pre-Release Center, his eyes sparkle and his hands fly into animated gestures. "I would never have thought of doing this," said Christakis, who spends 40 hours each week coordinating recreational activities and helping supervise inmates, "but I love my job."

A Yale University junior, Christakis, who lives in Chevy Chase, began working at the center during the summer.

He is taking a semester off from his pre-med studies at Yale to continue his volunteer work.

"I'm learning so much," he said. "I'm getting a kind of experience you just can't get from school."

Carl Clemmons, 14, who lives in the District, first heard of the YVA program from his counselor at Eliot Junior High. Clemmons, whose interests include "music, accounting, banking and clerical work," wanted to explore one of these as a possible career.

He volunteers in the membership department of the Wilderness Society every day after school.

"I like it a lot," said Clemmons, who types and answers telephones.

"It's fun, it's exciting and I'm learning something."

The youth volunteer program is an offshoot of the eight-year-old D.C. Volunteer Clearinghouse that matches adults interested in volunteer work with organizations that need them.

James Lindsay, executive director of the clearinghouse, said he became interested in a volunteer program for youths when he noticed that 63 percent of those who came to volunteer were students.

The YVA program, which has a one-person staff, is housed in the offices of the clearinghouse at 1313 New York Ave. NW. It is one of 85 similar youth volunteer programs across the nation.

All the programs are funded for their first two years with $20,000-per-year grants from the federal Volunteers in Service to America.

After that, however, each program must develop its own funding.

"There has been a tremendous increase in the number of students interested in volunteering," said Lindsay, including many students under 14, the minimum age.

Lindsay said he hopes to expand the program to include these younger volunteers.

"Helping others while helping yourself" is the slogan of the District of Columbia's young volunteer program, Cotton said.

He emphasized that voluntarism should benefit the volunteer as well as the agency.

"Volunteering is not only to get students out into the community," Cotton said.

"It's also an opportunity for young people to gain self-confidence, explore career interests and learn job skills," Cotton said.