Students at Cardozo High School aren't expected to amount to much, Mayor Marion Barry told graduating seniors at the school yesterday. Their school is in the heart of a drug-infested Northwest Washington neighborhood, they make the lowest scores in the District on standardized tests, and they come from a community where 40 percent of the residents are high school dropouts and the unemployment rate is the city's highest.

But this fall, about 50 percent of Cardozo's class of 1986 seniors will attend college, majoring in such fields as communications, education and engineering.

In other low-income areas, less than 30 percent of the seniors attend college. So the unusual success of Cardozo's 208-member graduating class triggered a special and curious commencement celebration, with Barry, teachers, counselors and school administrators bestowing deep sighs of relief and words of praise as well as diplomas.

"Someone asked me the other day, 'Can any good come out of Cardozo?' " Barry said. "This graduating class proves that a lot of good can come out of Cardozo."

City Council member Frank Smith (D-Ward 1), who represents the community where Cardozo is located, echoed Barry's sentiments. During the past three years, he said, he met several of the students and found many tardy and disruptive.

"Frankly, I had my doubts about some of you . . . ," he admitted. "But I'm glad to see you here."

Cardozo Principal James Williams, formerly the principal at Cedar Knoll, a city youth corrections facility, said in an interview that when he was assigned to Cardozo three years ago, he launched a special effort to "turn around" its students. Williams said he never thought the low test scores were an accurate reflection of the students' abilities.

"People wrote off most of these kids . . . other schools kicked them out," he said.

The principal said most of the students hadn't wanted to go to college because they were afraid that they couldn't afford it. So he began requiring that all seniors apply for financial aid. This year's seniors, he said, have qualified for or won more than $500,000 in federal funds, loans and local scholarships to cover the costs of four years of higher education.

Several graduates said Williams always "preached" to them that in order to live comfortable lives they would have to go to college or trade school.

"We are proud" of class valedictorian Crystal Jackson, salutatorian Amperita Wiley and other honor roll students, Williams said during graduation ceremonies. But he also paid tribute to a few students "who the system said were not going to make it."

Raynell Mangum, 19, who plans to attend the University of the District of Columbia and major in business management, said she would have dropped out of school without the interest of Williams and Cardozo's teachers and counselors.

"My biggest problem was learning how to take orders," she said. "I got high a lot and wasn't coming to school on time. I made Ds in my classes. But Mr. Williams kept telling me that I needed to control my temper and if I did that I could do something with my life."

Jason Rosebar, 18, whose parents were dropouts, said he "used to fight a lot. But the people here at Cardozo kept saying, 'You can't make it unless you do what we want you to do,' and that was study and do the right things."

In the commencement address, the Rev. Lewis Anthony, who directs D.C. Del. Walter Fauntroy's congressional office, told the graduates, "People said that you couldn't make it, but you laugh today because you did . . . we expect a lot of things from you."