ONLY A FEW years ago, the future of vocational education in the District's public schools looked bleak. Fewer and fewer teen- agers saw the programs as promising. Those who enrolled attended sporadically. On school days in 1980 at the Phelps Career Development Center in Northeast, nearly a quarter of the students were absent. At the Chamberlain center in Southeast, almost a third of the students were absent every day. Two years later, enrollment in the school system's six career-development centers had fallen from 2,745 students to 2,051.

In the 1982-83 school year, however, officials began costly renovations of each career center. The work was completed by the start of classes last fall. A new center, opened last month at 17th Place and Jasper Road in Southeast, is the first east of the Anacostia River. The centers were also paired with regular District high schools, meaning that students now attend a center half a day and a regular high school -- with the benefit of the identity and activities of that high school -- during the other half of the day.

The results are encouraging. There are now 3,700 enrolled in the career centers. Although 400 are now adults, the number of teen-agers taking part is still the highest the school system has ever recorded. Attendance has gone up, although much work is still needed.

The school system says that the centers' job-placement rate is about 75 percent. These are entry-level jobs in everything from cosmetics to carpentry. Keep in mind that over 40 percent of the nation's black teen-agers cannot find work at all.

The school system has also launched five career high school programs in conjunction with private firms and associations. Students in the pre-engineering program at Dunbar High School, for example, work with employees of General Motors, IBM and Pepco. The test of this program -- whether graduates gain enrollment to college programs or find jobs -- will not come until June 1986. The school system's culinary arts program, however, has 40 graduates so far. All but two are working as chefs.

The District school system is on the right track in strengthening vocational education and career training. The reasons include the city's strong interest -- including more money -- in the success of those programs and the addition of actual job holders as mentors and teachers. The latter marks a collaboration that should help lessen a traditional problem with vocational education: the fact that too many wind up with only partial training in obsolete techniques.