Arlington became the fifth Washington area school system yesterday to release standardized test scores showing a gap in the performance of black and white students, saying the performance of blacks in the county schools lagged behind whites by as much as 46 percentile points.

The disparity troubled school officials, who said they plan to examine existing programs for minority students and consider new ones.

"I don't think there's a magic program" to improve minority student scores, said Superintendent Arthur W. Gosling, in his first month as head of the county schools. "It has to be a multiplicity of things, but mostly it has to be a commitment from people who say, 'We want to do something about this.' "

Arlington officials said they have known about the problem and have programs designed to narrow the gap. "It's a frustrating situation . . . and we just haven't been able to find the right solution yet," said School Board Chairman Gail H. Nuckols. "But that doesn't mean we're going to stop trying."

Discrepancies between the standardized test scores of blacks and whites have drawn attention in the region as Alexandria and Fairfax, Montgomery and Prince George's counties each have released tests results showing disparities in their schools.

Results of Fairfax students on the Science Research Associates test, released Wednesday, showed the scores of blacks trailing those of whites by as much as 36 percentile points. In Alexandria, blacks' scores lagged behind whites' by as much as 48 percentile points.

The scores of blacks and whites in Arlington varied as little as 21 percentile points, on the sixth-grade language arts test, and as much as 46 points on the second-grade educational ability and 11th-grade reading test.

The widest gaps were in the test results for 11th graders, which showed blacks scoring below the national norm of 50 in all eight test categories. Asian and Hispanic 11th graders also scored below the norm in all categories except math. "The 11th grade scores are very bothersome," said Nuckols.

In general, the scores of black students, who make up 16.2 percent of the students, have increased over the last three years -- as much as 20 percentile points in the sixth-grade educational ability test -- while the scores of whites have been more steady.

Hispanic students, who make up 13.2 percent of Arlington's 14,600 students, generally scored slightly higher than blacks. Asian students, composing 14.3 percent of the students, tended to score higher than black and Hispanic students, but lower than whites.

Last year the Arlington school system launched a $160,000 program for underachievers in seven elementary schools. Ninety-six third and fourth graders, about 75 percent of them black, were enrolled in the half-day program of intensive classes in math, English and communication skills.

By the end of the school year, 65 students remained in the program, 12 returned to regular classrooms and Three were assigned to special education classes.

This fall, Washington-Lee High School began a program for underachieving freshmen and sophomores, who will attend intensive classes in English, math, science and social studies.

Gosling said school staffers will review the achievement of minority students and issue a report by January. Some school officials said the problem, rooted partly in socioeconomics and partly in teachers' expectations of minority students, may persist until teachers learn to think differently.

Frank K. Wilson, the only black member of the Arlington School Board, has been a strong advocate of the elementary school basic skills program, but noted that "You can put in all the programs you want, but if the child doesn't perceive that the teacher really cares, he won't achieve."

School Board member Dorothy H. Stambaugh said workshops for teachers might help make them aware of their varying expectations, not only of minority students, but of other groups. "At the elementary level, teachers have different expectations of boys than of girls, and of the troublemakers than of the quiet ones," she said.