Three Harvard sophomores last week learned they would receive scholarships from the Harry S. Truman Foundation, a prestigious fund established by Congress in 1975 to aid college sophomores interested in public service careers.

This year's Harvard recipients--all Social Studies concentrators--are: Lucy H. Koh from Oklahoma, Basilios E. Tsingos from New Hampshire and Melody R. Webb from Washington, D.C.

The scholarships, of which 105 are awarded each year, cover academic and living expenses of up to $7000 annually for up to four years, beginning in the junior year. Because Harvard's total fees are nearly three times that amount, Harvard-Radcliffe recipients will receive the full grant. If they choose to attend graduate school, they will receive the scholarship for two years beyond college.

Tsingos said that when he heard he had been chosen, "I went berserk. I flipped a little bit. I think I woke my roommate up."

All six of the Harvard nominees reached the semifinals, five were finalists, and three won scholarships.

In addition to the winners, Marc A. Bodnick of Massachusetts and Fidel A. Vargas, Jr. of California were named alternates. Either may receive a scholarship if a winner in his state declines the award, said Kristine Forsgard, fellowship director in the Office of Career Services, said yesterday.

Last year Harvard and Radcliffe had four winners, but Forsgard said, "The fact that we had so many finalists is unbelievable. The fact that two of these individuals are alternates is still amazing," she said.

Malcolm McCormack, executive secretary of the Truman Foundation, which administers the scholarships, said the award was founded because those who had known the president believed he would not have wanted a memorial building. "He was not much on bricks and mortar. They wanted a living program dedicated to Truman's memory," he said.

"We interviewed 276 finalists," said McCormack. "The final group of 105 consists of 55 women and 50 men from 63 private institutions, 42 public, and 3 community colleges. I'm pleased that we have more women than men this year."

To be eligible for the competition; sophomores must apply for nomination by their houses or by academic departments related to public service Candidates must also show they plan careers in government.

Colleges may nominate three students apiece, but because Harvard and Radcliffe are counted as separate institutions, the University nominates six undergraduates each year.