What will it take to make American educators face the truth that no standardized test can ever measure the potential of American high-schoolers who come from incredibly diverse backgrounds of deprivation and opportunity?

When will colleges and universities concede that the Scholastic Aptitude Test (SAT) and the American College Testing Program (ACT) can only give them fragile and often inaccurate data on which to base their admissions policies?

All these tests are skewed by the fact that millions of black and poor white kids have tried to learn under circumstances of shameful deprivation; that Hispanic and other Americans whose mother tongue is not English are at a disadvantage in both reading and writing essays and that there is an enduring notion in this society that females in high school don't need to take as many math and science courses as males.

I am moved once again to decry this slavish adherence to "aptitude" and "assessment" tests because the College Board, which administers the SAT for 1.3 million high school students each year, has announced revisions that are supposed to better measure critical thinking and problem-solving skills.

Over three years of administering a scholarship program called "Project Excellence," I have seen that within black America the youngsters who are the most compelling speakers, and who have a fiery yearning for success burning in their bellies, are frequently those who have known the most poverty, have grown up without the shelter of a real family and who have lived day-to-day within the squalid pressures of drug and sex abuse.

These are youngsters who often have risen from D students as high school freshmen to A students as seniors. Neither an SAT nor ACT score can tell any college dean of admissions of the shining potential of these youngsters.

Donald M. Stewart, the black former college president who is now president of the College Board, says the changes in the 2 1/2-hour SAT exam were not provoked by complaints that the test is "culturally biased" against minorities and women. It appears, however, that math and other questions are being changed so as to deny an advantage to students who are affluent enough to hire "coaches," as contrasted with poor youngsters who cannot afford the SAT-prompters.

As a college math major, I am fascinated by this old multiple choice question: "A baseball team has won 10 games and lost 5 games. If the team wins the next k games, it will have won 80 percent of all the games it played. What is the value of k?" With choices of 2, 3, 6, 8 and 10, a fifth of students might guess the correct answer of 10. Under the system to take effect in 1994, students will have to reason out the answer with no multiple choice help, which on its face seems a fairer test.

But it is not fairer to poor kids in inferior schools whose teachers cannot reason out the answers to such problems. It is no help to youngsters who don't have access to computers and the calculators that the College Board has now approved for usage in taking the SAT.

I don't expect the SAT and ACT people to cry "impossible" and walk away from their efforts to say which child deserves the attention of a nice college. The testers do serve many useful purposes. And there is a lot of money being made on giving such tests.

I just want the people who decide on college admissions, who give student aid and who gauge qualities of future leadership to understand that the tests have been, are and always will be flawed instruments.

We can't afford to have the dreams of marvelous, but deprived, youngsters flushed away with shredded tests of dubious merit.