The gap in standardized test scores in reading and mathematics between Arlington's white and minority students remains significant, but has narrowed in some grades over the last three years.

Superintendent Larry Cuban released the ethnic breakdowns of the Science Research Associates (SRA) test results last week. Cuban said he is "very gratified by the emerging pattern," but cautioned that the school system "has a long way to go" to bridge the gap.

He attributed the improvements, particularly those among elementary students, to "staff concentration on basic skills over the past seven years" and to special programs for minorities.

The overall county results of the SRA tests taken nationwide last fall were released in January. For the third consecutive year, Cuban voluntarily disclosed the breakdowns for ethnic groups, which comprise nearly one-third of the 15,146-pupil school system.

Test results were released for white, black, Asiatic and Hispanic students in the fourth, sixth, eighth and 11th grades. For all results, the national norm is at the 50th percentile. Gains or losses from the previous year of five points at the elementary school level and eight points in the higher grades are considered statistically significant. Among the findings from the tests taken last fall:

Fourth grade reading results: Whites, on the average, scored in the 84th percentile. Blacks jumped significantly from the 43rd percentile last year to the 51st this year, but still trailed Hispanics who scored in the 55th percentile and Asiatics who scored in the 63rd.

Fourth grade math: Whites and Asiatics scored in the 78th percentile and Hispanics in the 59th. Blacks again jumped significantly from the 45th percentile last year to the 54th this year.

Sixth grade reading: Blacks jumped 12 points over last year, registering in the 48th percentile, but they still fell behind the other groups. Whites increased seven points over last year to the 85th percentile while Hispanics gained a 10-point edge over last year, scoring at the 58th percentile. Asiatics also improved over last year, scoring at the 62nd percentile.

Sixth grade math: Hispanics jumped 13 points to the 72nd percentile, blacks 10 points to the 53rd, whites eight points to the 88th and Hispanics seven points to the 85th.

Eighth grade reading: Asiatics dropped 16 points to the 32nd percentile while Hispanics jumped eight points to the 40th. Whites increased five points to the 70th percentile, but blacks made only a three-point increase to the 23rd percentile.

Eighth grade math: Asiatics fell, by eight points, to the 72nd percentile while Hispanics gained 18 points, scoring in the 59th percentile. Blacks gained 10 points to the 43rd and whites gained four points, to the 72nd percentile.

Eleventh grade reading: Asiatics dropped 20 points to the 21st percentile while Hispanics increased 10 points to the 51st. Whites increased four points to the 66th percentile, but blacks remained constant at the 21st, where they have been for three years.

Eleventh grade math: Whites remained at the 66th percentile for the third straight year while blacks increased by six points to the 29th. Asiatics dropped eight points to the 55th and Hispanics dropped 10 points to the 40th.

Students in the higher grades traditionally do not make the improvements on scores that those in the lower grades do. Cuban speculated that one reason for the difference in the results may be that the older students did not have long-term exposure to remedial programs now available in the schools.

Cuban also acknowledged that there are "many anomalies" that are hard to explain" in some of the results, such as why Asiatic students tend to score much higher than the other minority groups in most of the tests.