In a few years, college-bound students will have to give their own answers to some Scholastic Aptitude Test math problems instead of picking from multiple choices. But they'll be able to use a calculator.

Those are among changes announced Wednesday by the College Board, sponsor of the SAT, the most widely used college entrance exam in the nation.The revisions - the most drastic in the test's 64-year history - also include more emphasis on reading comprehension. The revised SAT, called SAT-I, will be introduced in 1994, board President Donald M. Stewart said.

In addition, an optional test, known as the SAT-II, will be phased in starting next year and will include an essay section.

Critics who have charged that the test is culturally biased and a poor judge of students' ability said the changes don't go far enough.

"It's polish. It's adding new tailfins to the Edsel," says Bob Schaeffer, public education director at FairTest, a group based in Cambridge, Mass., that's critical of the SAT. "The SAT should be optional, and it should be comprehensively overhauled to address its problems."

Stewart said the revisions were aimed in part at reducing students' reliance on test coaches. The changes will increase the SAT's "educational relevance and quality for all college-bound students," he said.

He denied the changes were prompted by charges that the SAT is biased, particularly against women and minorities.

"Nothing could be further from the truth," Stewart said at the board's annual meeting in Boston. "The SAT has been in almost continual evolution. It has never been set in concrete."

Gregg Driben, national director of pre-college programs for Stanley Kaplan Educational Center Ltd., which prepares students for standardized tests, said professional coaches still will play an important role.