The Quality Market, a mom-and-pop store near Stuart Junior High School in Northeast Washington, was once a busy place at lunch time. Dozens of students would run into the store and scramble for sodas, candy and pastries.

Nowadays, it is quiet and lonely inside the store, said owner Min Chang, because "the police catch kids when they come in here and take them back to school. Very few kids try to come in here for lunch. Very few."

The lunch-hour emptiness in the store is one indication that a policy passed by the D.C. school board this year prohibiting junior high school students from leaving school grounds during lunch is apparently working.

Under the "closed campus" policy, which is strongly supported by parent groups, 19,000 teen-aged students at 27 junior high schools can leave during lunch only if they have written permission from their parents. Those caught off school grounds illegally are to be reprimanded and suspended, and their parents are to be notified.

R. David Hall, president of the school board, said, "The closed campus policy is part of our plan to tighten up the schools. It helps students get back to school on time after lunch because they aren't hanging out on the streets. . . . This is not an experiment, it's permanent."

Hall said school officials have not conducted a survey to determine the effectiveness of the policy, but several junior high school principals across the city said in interviews that the policy is working well.

School food service officials reported a 5 percent increase in the number of lunches served at junior high schools in September, although the number of junior high school students had declined. October figures are expected to reflect a larger increase because more students have become accustomed to the new rules, they said.

"We planned to have about 10 to 15 percent more junior high school students eating this year compared to those who did so last year," said Samuel Foster, deputy chief of the food service branch.

"All of the schools are trying to enforce the new policy, but at some schools it's difficult because of space limitations and other considerations," he said.

For instance, at Lincoln Junior High School on 16th Street NW, with an enrollment of nearly 1,000 students, administrators are having problems enforcing the policy because gates are missing from the fence surrounding the playground. As large crowds of students gather in the playground during lunch period, some sneak away from the school by walking through one of several gaps where there should be gates or where fence repairs are needed. Few are caught.

"A lot of children leave school for lunch," said a 15-year-old eighth grader, who was returning to the school recently carrying a bag of hamburgers and french fries from a fast food restaurant.

"The policy doesn't work here because the campus is not secure," said a guard at the school. "Until those gates are replaced, it won't work."

Lincoln Principal Christine Burgess said that in the spring, school custodians surveyed the property and asked school officials to install the gates. "We had the place surveyed and identified where we needed gates. The Buildings and Grounds Division is aware of the problem. We've made more than one request, and we're in the process of waiting for a response," she said.

Two supervisors in the school system's Buildings and Grounds Division confirmed that the request for new gates has been received but said the work order has not been prepared.

Across town at Evans Junior High School, 5600 East Capitol St., Michele Williams, 14, a ninth grader, strongly objected to staying at school during her only free hour during the day and eating "yucky" cafeteria food. "They treat us like kindergartners. This is supposed to be school, not prison. We want out," she said.

But Evans Principal Margaret Saxon said that the new policy is a good way for Williams and other students to learn to respect and appreciate the often restrictive responsibilities of adulthood.

"When students were allowed to leave for lunch, many of them had problems getting back on time, and some skipped afternoon classes altogether, she said. "Some would get into mischief and throw midday parties at home. Now, we don't have to worry about that."

Parents have been very supportive of the policy, she said. Of 425 students at Evans, only three have passes to leave during lunch, and those are "for medical reasons."

For some schools, "closed campus" is nothing new. For example, Backus Junior High School at South Dakota Avenue and Hamilton Street NE, has sponsored lunchtime study sessions, dances and games for students for 20 years, said Principal Edmund Millard.

Min Chang, echoing other owners of stores near schools, said the new policy makes it hard on business, but, "It's a good idea. For business, I don't like it. For education, I like it."