The Educational Testing Service in Princeton, N.J., has done it again -- got caught with its integers down.

An integer, for those who don't know, is any positive or negative whole number such as 8 or -2. The Scholastic Aptitude Test, which ETS administers every year to thousands of high school students hoping to gain admission to college, includes questions about integers. ETS uses panels of scholars to determine what the right answers are.

But for the second time this month, the testing service has been forced to admit what it considered the only correct answer to one of its questions was, in fact, not the only correct answer.

"Much to our chagrin, it's another math item," said Larry Gladieux, executive director of the Washington office of the College Board, said yesterday.

The College Board is a long-established organization of colleges and universities that establishes certain standards for its members governing such questions as college admissions. It contracts with ETS to administer the SAT to high school juniors and seniors. The test results are widely used by colleges in determining what applicants will be admitted as freshmen.

ETS's first embarrassing error was uncovered by a 17-year-old Cocoa Beach, Fla., high school student who challenged the "correct" answer on the Preliminary Scholastic Aptitude Test.

The latest error was also discovered by a high school student, one of 87,000 who took that SAT test in New York state, according to a statement from George H. Hanford, president of the College Board.

ETS makes the correct answers to the preliminary aptitude test available to any student who asks for them. It does not release the correct answers to the SAT tests except in New York, where it is required to do so by a state law.

The disputed question on the New York test asked students to choose the one row of numbers (from a list of five rows) that contained "both the square of an integer [whole number] and the cube of a different integer."

ETS said the "correct" answer was row B, which included the number 8 (the cube of 2) and the number 9 (the square of 3).

But the unnamed New York student had marked row C and he thought he knew as much about it as ETS's panel of mathematical wizards. It turned out he was right because negative numbers also count in this business. Row C contained the number 4 (the square of -2) and the number 8 (the cube of 2).

It is a rule of mathematics that minus numbers, when multiplied, produce a positive number as a result.

As a result of the error, the scores of about one-fourth of the students who took the test in New York and marked row C are being increased. The correction will boost their scores, depending on the pattern of their other right and wrong answers, by about 10 to 20 points on the SAT's 200 to 800 range.

About half of the 87,000 students marked the officially correct answer and will continue to receive credit for their answer.