COLLEGE FRESHMEN know less than they

used to. This is not because the basics are being slighted in the early grades: there is encouraging evidence that elementary schoolchildren are doing better on standardized achievement tests. The reason is that high school students are learning less.

Most American high school students don't work very hard. Yet "grade inflation" gives them better grades than when the decline in achievement began 20 years ago. At many schools, a modestly intelligent student can get straight A's with minimal effort--and less learning.

Christopher Jencks and James Crouse, professors of sociology and education respectively, have looked at these facts and made a provocative proposal. They suggest that the emphasis placed on SAT scores (the Scholastic Aptitude Test is taken by nearly everyone who wishes to go to college) contributes to a lackadaisical attitude by reinforcing the idea that academic success depends on inherent ability rather than on sustained hard work.

Educators know that despite its name, the SAT does not measure an inherent, unchangeable potential. It is in fact an achievement test that measures what has been learned of some central academic skills, rather than of the content of particular subjects. But many students, parents and teachers believe that the SAT is a true aptitude test. Those in the testing business believe that since the SAT was designed to measure future capacity to learn rather than what has already been learned, the test is properly named.

Profs. Jencks and Crouse challenge that belief. They cite admittedly incomplete evidence that achievement tests predict future academic success about as well as the SAT. Nor, they say, does the little existing evidence support the assumption that the SAT is better at identifying good students, including minority students, who have had to attend bad schools. So they suggest that the SAT's name be changed so as to help drive home the view that work --not God-given potential or socioeconomic status-- makes the difference for most people.

They go further by suggesting that selective colleges base admission on achievement tests rather than on the renamed SAT. This, they believe, would force those who want to go to a good college to work harder in high school. Though the change would directly affect only a fraction of students, it would have a ripple effect on others and on the goals of secondary school teachers and principals.

It is an interesting idea with a ring of good sense to it. It has already provoked a useful debate among educators, and it deserves wider discussion.