Spilling out of Langley High School in McLean Saturday morning, scores of juniors and seniors were pale, wobbly and relieved, after facing the most wrenching statistical challenge of their educational careers -- the Scholastic Aptitude Test.

For many of them, the grueling three hours of intellectual slugfest wasn't their first go-round. Sebastian DiPinto, 17, a mild-mannered senior at Langley High, was back for his third time. When he first took the SAT last January, DiPinto tallied a 940 (combined verbal and math scores). Knowing that wouldn't bode well for his applications to competitive schools, among them the University of Virginia and Cornell, he took the tests again last June and scored 1,110. No sure thing either.

"I'm hoping for 1,250," DiPinto says of his latest attempt. "I thought I could do better because I have a really bad vocabulary. I started studying and I think I had a lot of room to improve my score."

Eddie Chang, 17, a Langley senior with a respectable 3.7 grade average, has taken the SAT twice and worries that colleges will brand students who take it too often as desperate. "Not too good" is all he'd say about his score the first time. But he admits that if his Saturday tests don't total 1,350, he may try again in December. "It is a consideration," he says somberly.

"I heard of one guy last year who took them three times and got 1,500, and still didn't get accepted where he wanted to go because he was such a grunt," says Peter Hoffman, 17, a Langley senior who's applying to Denison University and Ohio Wesleyan. On Saturday Hoffman took an ETS Achievement Test, not the SAT. He may be atypical of his classmates. He has taken the College Boards only once, last June, and scored 1,200. And he said he's not taking them again. "That's good enough for the schools I'm applying to," he said. "I guess I'm kind of a dork just taking them once and being satisfied."

When it comes to SATs, also known as the College Boards, many students buy into the notion that, if at first you don't succeed, try, try again. The prospect of raising verbal and math scores (each of which range from 200 to 800) to add a little extra weight to a college application is very seductive to high-strung high schoolers certain their entire futures might be made or broken with a No. 2 pencil on a Saturday morning in November.

But some educators and college admissions specialists doubt whether two-timing (or more) the SAT often makes an appreciable difference in getting into any particular college. Many of them say students mistakenly give the SAT scores unrealistic importance and, thereby, decide once is not enough -- when it probably is.

Question: Describe the phenomenon of college applicants feverishly retaking the College Boards to up their scores?

(A) the S.A. Tease

(B) an Admissions Control System

(C) a waste of time and money

(D) all of the above

The correct answer is D, according to some educators.

"The rule of thumb is that students take the test in May of their junior year and again in November of their senior year," says Ray Nicosia, a spokesman for the Educational Testing Service, the company in Princeton, N.J., that devises and publishes the SAT, among other tests regularly required by college admission offices. Indeed, ETS's testing schedule is most accommodating. Those students who took the SAT Saturday morning, which is annually the largest turnout date, can choose to take another version of it a month later, on Dec. 1, or wait for any of four other dates before the end of the school year.

And ETS's statistics indicate many of them will: Of the more than 1.5 million students who took these tests during the 1989-90 school year, 55 percent did so once, about 36 percent took it twice, 7 percent three times, and about 1 percent four or more times. "We'll tell a student that if he's unhappy, try it again," says Nicosia. "There's always someone who will take it three or four times."

Is it ever worth it? On the average, a student who takes the $14.50 test twice within 6 months, continuing ordinary school work in the meantime, can figure on his combined verbal and math scores going up about 25 points, according to ETS. Only problem is that the scores of 35 to 40 percent of those same students are likely to go down, reflecting perhaps the standard 30 point (up or down) margin of error on each of the SAT parts.

For students who formally prepare for the repeat performances, the average gains are higher. After 30 hours of instruction in verbal skills, the scores jump an average 15 points; 30 hours of reviewing math skills nets 25 points. That's an average of 40 points' difference on a 1,600 combined point test. To do much better than that, advises one ETS report, would require practice and review that approximate full-time schooling.

"Some familiarization is good but you have to draw the line on how much time you want to spend," says Nicosia, who recommends students spend their time bringing up their grades, working for charities or tackling extracurricular projects at school rather than devoting 60 hours to prepare for taking the SAT again. In fairness, ETS informs students that, besides their scores, colleges take into consideration academic record, extracurricular activities and evidence of personal traits -- initiative, motivation, leadership. "To put all the eggs in one basket isn't a good idea," Nicosia says of the SAT. "No matter what they say, it is just one piece of the pie that admissions committees look at."

Yet, in the minds of many students, it remains the piece of the pie that's pie in the sky. As one Fairfax County educator said of some of her students contemplating yet another College Board bout, "They're under this grand illusion that seven points will matter. They say, 'Oh, I got seven more points!' And I say, 'Sweetie, why'd you spend the 20 bucks? You could've bought a new pair of shoes.' "

Okay, forget the seven points. No matter how anxious about their chances for Harvard, not many students are willing to suffer multiple-choice hell for seven points. But what about 50? Even ETS says that, with a little prep work, it's a realistic improvement. Could 50 matter?

"My guess is it would make no difference" to most acceptance decisions, says Charlie Morris, a psychologist and provost of Denison University in Granville, Ohio, who has conducted statistical analysis on SAT issues for Denison's admissions office. "If you got a kid with 800s and a kid with 750s, there's no difference. They're going to be in the top of their classes."

Lower scores may track a little differently, however, because low scorers are fighting real or abstract minimums in many admissions offices. So even modest gains can have an impact. "It could make a difference," admits Morris, "if it is somewhere near the cutoff point."

At the U.S. Naval Academy, for instance, this year's 8,000 applicants are being screened for about 1,300 slots. All must first be "scholastically qualified" by the admissions committee. "Initially, all they're sending us is their SATs, their Preliminary Scholastic Aptitude Test {a warm-up taken in sophomore or junior years}, and their class ranks. From that we set some criteria for cutoff levels -- where we think these candidates will be competitive at the academy," says Nick Pantelides, director of admissions.

Those whose scores aren't competitive are advised to consider retaking the SAT, he says. This inspires some Naval Academy applicants to retake the SAT several times; one is even rumored to have gone 15 rounds with the irascible exam. "I have seen candidates take them three or four times," says Pantelides. "Those going to prep school who have applied numerous years maybe take them seven or eight times."

Unlike his colleagues elsewhere, Pantelides isn't loathe to utter the word "cutoff." The Naval Academy prefers applicants with at least 520 verbal scores and 600 math scores -- though there are exceptions. But military academies operate differently from other colleges and universities. "We don't have the privilege to be able to fill a class once it has already started," he says. "So the scores give us an indicator of how well someone might do their freshman year. The scores are important. The SATs are probably the most visible part of the college process, and I think they're the most misunderstood."

Could raising a score 100 points be misunderstood by anybody? "Clearly, a student who raises his 450 verbal score to 550 represents a significant improvement," says Denison's Charlie Morris. "That's beyond the standard deviation. But I don't think you see that kind of improvement very often."

Morris enunciates what most college administrators try to impress upon college applicants: Getting into the college of your choice is much more than a numbers game. Take Denison, which is categorized as "very competitive" in most college guides. Morris emphasizes that Denison doesn't make its admissions decision based exclusively on SAT scores. No college does.

"We've got an average SAT composite between 1,050 and 1,100," Morris says of the working parameters for Denison's incoming freshman class. "But if we look at someone in the 950 range and they're in the top 10 percent of their high school class, we'd probably take them. Or we read their essay and they write well, we'd probably take them. Or if they show some evidence of initiative, that adds up to a kid that we'd be willing to take a chance on."

Fine. But what about gaining, say, 300 points total? "Suppose a person was able to increase his scores by 300 points," says James Crouse, a professor of educational studies at the University of Delaware, in Newark. "You would normally think their admissions chances have gone up because of their high SAT scores. But I don't think it would matter that much."

The author of the 1988 book "The Case Against the SAT," Crouse argues that the test scores are largely redundant of high school rank and grades. He figures that in about 90 percent of admissions decisions, colleges using only class standings would end up accepting the same students they accepted when adding the SAT scores into the equation.

"In the equation that is used to predict success, the number that they multiply SAT scores by is very, very small, a fraction," says Crouse. "So if you increased your SAT scores by 100, that 100 would be multiplied by a very small number, and it is likely to have almost no impact on your admissions chances. That, he argues, is true at a college such as the University of Delaware, where 90 percent of all in-state applicants will be accepted, as well as at highly selective colleges.

Besides, says Crouse, SAT scores are losing their edge in most admissions decisions. Colleges are using them mainly "to advertise their victories" and to serve as admissions gatekeepers by warding off unsuitable applicants, he says. "When colleges announce their SAT averages for their freshman class, this signals some students not to apply."

Students should avoid making the SAT a career in itself, advises Iris C. Metz, president of the College Preparatory Service, a Pittsford, N.Y., company that produces videos and guidebooks to assist college applicants. "There's a lot of anxiety, which is why taking it twice is sufficient. He shouldn't spend his time doing things that aren't going to give the same payback. Taking it in the spring and then in the fall is good strategy."

Such advice means little to Tarik Dahir and other high-school seniors strung out on second-guessing the college admissions process. Dahir took the SAT for the second time on Saturday, after scoring about 30 points below the average for freshmen accepted last year at the University of Colorado, at Boulder, his first choice.

"I'm expecting 1,300," says the Langley High senior. "I think I panicked the first time. I've had the experience now, and this time I want to gain 200 or more points."

And if he scores only the average increase predicted by ETS, about 40 points? "I definitely will consider doing it again," he says.