The College Entrance Examination Board, which administers the Scholastic Aptitude Test to high school seniors applying to college, has now released three illuminating reports. First, it announced that for the first time in 18 years, SAT scores had risen. Both verbal and math scores improved slightly in 1982. This news was joyfully received by educators and the public alike as an indication that a troubling national problem was on the way to solution.

Even before this euphoria had dissipated, the board revealed that the scores of black students continue to be significantly below those of whites. On a scale from 200 to 800, the median score achieved by black youngsters on the verbal test was 332 and on the math test 362. Comparable figures for whites were 442 and 483.

Now comes a fuller explanation of these statistics and with it a freshening of the belief that American schools are back on the right track after all. The board points out that most of the recent increase in scores is attributable to black students. While the gap between the races is still cause for concern, it is beginning to close. In this year's test, black scores rose an average of nine points on the verbal side and four points on math. Whites gained two points in the first category, but remained at the same level in the second.

Why is this happening? When SAT scores first began to decline in the '60s, many educators attributed the change to the dramatic increase in total numbers of high school students taking the college entrance exams and to the large number of lower-income children of all races that had become part of this group. But about 10 years ago, the number of those taking the test leveled off at just under a million a year and it has remained at that level. If this theory had been correct, the scores would have stabilized in the early '70s, but instead they continued their downward slide.

This year's good news can be attributed to important recent changes in the country's approach to secondary education. There has been a marked return to required courses in place of electives, a reaffirmation of the value of science courses and a renewal of mandatory foreign language teaching in these grades. The folly of laissez-faire grammar and reliance on oral rather than written reports has been exposed. All our children are being better prepared to take these tests and go on to college. The scores show that black youngsters are adapting to these standards with notable speed--and increasing success.