What was going on when I was born?

United States and Cuban negotiators have reached an agreement in principle on the terms for repatriation to Cuba of some 2,500 criminals and mental patients, Administration officials said today. In return, they said, the United States would resume the processing of regular emigration from Cuba to this country. They said that the negotiators, Michael G. Kozak, deputy legal adviser of the State Department, and Ricardo Alarcon de Quesada, the Deputy Minister of Foreign Affairs, had concluded a third round of negotiations in New York last week with an agreement conditional on the approval of both Governments. If they approve, an announcement could be made as early as Thursday, the officials said. This would be the first agreement between the two Governments since the Reagan Administration took office, but Administration officials stressed that it was limited strictly to immigration matters.

P. Michael Timpane, a former director of the National Institute of Education, was inaugurated Friday as the eighth president of the Teachers College of Columbia University. In an interview, the 50-year old educator, who had been dean of the college since 1981, discussed his views on the state of teaching and teacher education. Following are excerpts from the interview. Q. Numerous states now have legislation providing for ''master teachers.'' Do you think this is a good idea? A. A great problem in the teaching profession is that it is so flat. You enter a classroom as a teacher, and unless you choose to leave the classroom to be a specialist or a supervisor, you're a teacher forever. There are not additional levels of responsibility and competence that are recognized and rewarded. I believe that some variation of the career ladder approach, with master teachers being one variety, is a good idea. There is also room for teachers who specialize in research, teachers who specialize in curriculum development and other models.

Jobs in many suburban stores are going unfilled during the holiday shopping rush, forcing employers to find new ways to attract part-time and seasonal help. Abraham & Straus, the department store chain, is busing young people from Brooklyn who have had trouble finding employment in the city to its stores in Paramus, N.J., and Manhasset, L.I. In northern New Jersey, Westchester County and Long Island, the shortages are similar to those of the past summer, when some suburban teen-agers shunned jobs at shopping malls or at the beaches that paid the minimum wage of $3.35 an hour. Many employers said they have never had so much trouble finding extra workers for the holidays. The shortage comes at the time of year when retail stores make 25 percent to 30 percent of their yearly sales. The shortage of employees is apparent in longer lines at checkout counters, poorly stocked shelves and signs in many store windows announcing that help is wanted.

The status of the President's science advisory office is in a state of flux that may leave it greatly strengthened or perhaps weak ened. The most dramatic proposal is to create a Cabinet-level Department of Science and Technology that would take over much research now being administered by other departments. Last week the President's Commission on Industrial Competitiveness, which is made up of industry leaders and George A. Keyworth 2d, the President's science adviser, finished a report in which it called on the Government to establish such a department to spur industrial innovation. Although the commission was officially silent on the scope of the proposed department, members informally said it might consolidate up to six Federal programs and agencies whose budgets this year total about $15 billion. ''What we're saying is that the future of the nation depends so critically on technology that it needs a stronger voice in Government,'' said Ian M. Ross, president of Bell Laboratories, a co- chairman of the commission's committee on research and development. ''Such a department would transform the current, fragmented formulation of policies for science and technology into one that would be far more effective in meeting long- term national goals,'' the commission said in its report.

An article in SportsMonday yesterday about the New York Giants' loss to the St. Louis Cardinals misstated the length of Ali-Haji Sheikh's field- goal attempt in the third quarter.

When President Reagan took office, he championed an approach to tax policy that greatly expanded incentives for specific types of business investment. This program has been credited with helping spur a recent surge in capital investment. Now, however, if the President endorses the Treasury's plan for overhauling the tax system, many economists feel that he would be abandoning this strategy of encouraging production through tax incentives - a strategy favored by supply-side theorists, among others - in the hope that free-market forces would nurture fruitful investment. Some analysts fear that removing these tax incentives would hurt business investment that they consider crucial to economic growth. ''For all the rhetoric we've heard about supply-side economics, this is sort of an anti-supply-side approach,'' said Nariman Behravesh of Wharton Econometrics, a forecasting and consulting firm. ''It provides a disincentive for investment.''

A RACE is on between those seeking to make the oceans transparent and those who want to keep them opaque. The race is pitting American and Soviet designers of submarines against Soviet and American designers of systems for detecting submarines. The submarine designers on both sides pursue ways to make their vessels ever harder to see and hear, while the experts in antisubmarine warfare keep developing ever more esoteric devices for ''seeing'' underwater so they can find and track submarines. The outcome of this technological race will determine whether missile- carrying submarines continue to be the almost invulnerable deterrent to nuclear attack that they are today. Despite efforts to make the oceans transparent, it appears that American missile-bearing submarines will be able to remain hidden for a long time. This is soon expected to apply as well to the newer, quieter Soviet submarines.

THE cornea of the eye, one of the first human tissues to be transplanted successfully, is being used more widely today than ever before to restore sight to the blind. Corneal transplants have been done successfully since the 1940's or even earlier. They are now being performed in the United States at the rate of more than 20,000 a year using corneas gathered by at least 95 eye banks, according to the Eye Bank Association of America. The association estimates the number of corneal transplantshas tripled within the last five years.

American astronomers have discovered what they believe is the first planet to be detected outside the solar system, it was announced yesterday. In observations with an infrared telescope last summer the astronomers found a huge, gaseous object orbiting a dim and distant star in the constellation Ophiuchus. They believe the object is nine- tenths the size of Jupiter. But its mass or density is estimated to be 30 to 80 times as great as Jupiter's. Jupiter, which is also gaseous, is the solar system's largest planet. The object's surface temperature was estimated at 2,000 degrees Fahrenheit.

Some Reagan Administration economists and many of the nation's leading economic forecasters find that the Treasury's new tax plan would be more likely to retard the nation's economic growth than to accelerate it, at least during the rest of the 1980's. This is contrary to the Treasury Department's expectations that the plan would foster growth. ''It's unfair,'' Treasury Secretary Donald T. Regan said of the present tax code when he announced his plan two weeks ago, ''and it retards saving and investment and economic growth. It must be changed.''

The Economy The Treasury's tax plan may retard economic growth, rather than accelerate it, at least during the rest of the 1980's, according to some Reagan Administration economists and a number of the nation's leading economic forecasters. This is contrary to the Treasury Department's expectations that the plan would foster growth. (Page D1.) The tax plan could also hurt business investment, some economists feel, by removing certain tax incentives that they consider crucial to improving productivity and long-term growth. (D1.) The Council of Economic Advisers may be abolished as part of the President's cost-cutting program, the White House said. (D1.)

Relatives and neighbors of Sharon Walker clustered in front of her aging row house in Jamaica, Queens, yesterday, their tears dried and their anger rising, trying to understand why the young mother of three was shot to death over a minor traffic accident. That was essentially the question being asked in the police precincts of Queens, too. For on Sunday afternoon, 16 hours after the accident and Miss Walker's shooting, the police had arrested one of their own, Sgt. Rudolph Hays, a member of the force for 33 years, and charged him with second- degree murder in the slaying. ''She loved everybody, she hurt nobody,'' said Shirley Goss, the sister of Miss Walker, who was described by neighbors as a constantly cheery woman dedicated to her job as a therapist at the nearby Creedmoor Psychiatric Center and to raising her three teen-age children alone.