What was going on when I was born?

IT is a bad dream shared by many Americans - the vision of being confronted on a dark street by a man who pulls out a gun to terrify you into surrendering what you have. This dream, which has become reality for many people in recent years, raises some of the most troubling of possible questions: What do you say, or do, to stay alive? How do you talk to a man with a gun? How likely is an armed criminal to shoot, and how can you influence his choice? Recent studies by behavioral scientists have shed light on what happens in robberies and other violent crimes and what steps a person can take to protect himself. Two major conclusions are highly relevant to the city dweller. First, the victim of an armed assailant is most likely to escape harm if he is deferential and quickly gives over his goods. Second, the victim of an unarmed criminal is most likely to prevent or escape the robbery or assault if he offers nonforceful resistance, such as yelling or running.

This is a tropical revolution, sprawling in the heat and wild rain, not quite contained by ideology or plan. Up close, Nicaragua, which President Reagan describes as part of the Soviet-Cuban axis, is more strikingly a place stumbling in its own contradictory slogans, handing out ration cards, waiting in line for gas, for beans. The soaring promises of the 1979 Sandinista insurrection - political pluralism, a mixed private-and-state economy and international nonalignment - are gone, replaced by opened mail, People's Tribunals, smothered debate.

'' It seems to me that in looking for ways to resolve new tasks we were not vigorous enough, that not infrequently we resorted to half-measures and could not overcome the accumulated inertia fast enough.

After four years of medical school, five years of graduate training and months of all- night rounds, Dr. Michael Kressner, at the age of 32, was finally ready to open a practice in gastroenterology. The problem: No hospital would take his patients. For Dr. Rosemary Klenk, a pediatrician who is 35, there was a different problem: Money. Already $30,000 in debt for her medical education, she and a partner had to borrow $80,000 more to open an office in Connecticut. As for Dr. Dean Stetz, a 30-year-old ophthalmologist who is $25,000 in debt for medical training, his hope of opening an office in Manhattan remains distant. He says he cannot afford to borrow the $100,000 he thinks he will need to pay for malpractice insurance and rent and for his living expenses while he builds a practice.

The persistent heat wave and drought is not only shriveling the 1983 corn crop but also upsetting predictions about the effect of the nation's farm policy. And once again experts both in and out of the Administration are despairing of bringing the unwieldy and expensive farm program under control. For the Reagan Administration, which had committed itself to shrinking the cost of supporting farm income, the chagrin is particularly intense. Agriculture Secretary John R. Block is presiding over what are shaping up as the two most expensive years in the history of the farm program, costing $13.3 billion in 1982 and an estimated $21.8 billion in 1983.

Markets Stock prices posted a broad advance as hope spread among investors that Friday's favorable money supply report indicated an easing in the recent upward pressure on interest rates. The Dow Jones industrial average rose 10.67 points, to 1,193.50. On the Big Board, advances outnumbered declines by more than 2 to 1, while turnover expanded to 83.2 million shares. (Page D1.) Interest rates were mixed, with traders awaiting new evidence of the direction of rates. (D7.) The dollar continued to retreat, while gold prices rose $7 an ounce in New York, to $420. (D12.) Corn and soybean futures prices soared by their daily limits. (D12.)

All night and most of the day, the thunder of French military transport planes reverberates over this city, and the symbolism is evident. This is the bridgehead of Western support for President Hissen Habre's 13- month-old Government, it is the emblem of a reluctant commitment by the Socialists in Paris that has frozen the advance of Liyba's leader, Col. Muammar el-Qaddafi, into Chad, for the time being at least. But the triumph may turn out to be Pyrrhic. France, embroiling itself in a military adventure from which Washington shied away, has committed itself to an involvement that may be open-ended and that seemingly reverses the Socialists' aversion, while in opposition, to the interventionism displayed by President Valery Giscard d'Estaing.

The International Monetary Fund gave formal approval today to changes in Argentina's economic policies, an action that releases $1.8 billion in loans from commercial banks and a third $300 million installment of a standby credit from the I.M.F. The 146-nation lending agency held a rare August board meeting to review the situation in Argentina, which has nearly $40 billion in debt outstanding to foreign creditors. After Brazil and Mexico, which each owe more than $80 billlon, Argentina is the world's biggest debtor. The I.M.F. issued no statement, but monetary officials reached after the meeting said the action paved the way for Argentina to get the $300 million in September, subject to the clearing up of arrears to foreign creditors and an on-the-spot verification of money supply data. Argentina has so far drawn $624 million from a $1.62 billion, 15-month standby credit approved by the fund last January. It also borrowed $560 million in compensatory financing credits that are available to countries whose exports have been hit by the global recession. As with all I.M.F. loans, the money is being disbursed at close-to-market interest rates. The standby credits are subject to conditions agreed to when the loan is signed and are monitored periodically by the fund's staff.

William B. Tanner of Memphis has become well known in Southern broadcasting circles in the past 25 years for driving fast cars and hard deals. His company, the William B. Tanner Company, which buys and sells air time to radio and television stations - mostly on a noncash barter basis - has also become known for its ability to provide an unusual array of goods and services in his barter deals. From television cameras to basketballs, from American Express cards to inflatable boats, Mr. Tanner could satisfy his clients. Last Friday, the company became more widely known when Federal investigators raided its headquarters and spent seven hours going through its files. Acting on a search warrant that cited suspicions of income tax fraud and conspiracy, the agents seized boxes of documents and released the text of an affidavit signed by two former employees and a former client who alleged, among other questionable practices, that Mr. Tanner provided his clients with women and envelopes full of cash.

Because of an editing error, an article about the New York Jets in Sports Pages last Friday attributed a quotation incorrectly. The man who spoke of being asked by Oakland to scout an opponent's defensive backfield was Charley Winner.

FOR three weeks recently, in the unlikely setting of a small courtroom in New Brunswick, N.J., little-known and even less understood practices of the largest testing organization in the country came under rare scrutiny. At issue was how the Princeton-based Educational Testing Service goes about identifying possible cheaters, and what happens to students under suspicion. The trial, the result of a lawsuit filed by four recent graduates of Millburn High School who were suspected of cheating on their college entrance examinations, ended with a ruling favorable to the testing service. Judge Richard S. Cohen of the Chancery Division of Superior Court said the testing service had acted fairly in questioning the scores of the students, whose guilt or innocence as such was not at issue in the trial.

STANDING in one geologic time zone and reaching up toward another, Bill Clemens addressed the side of a bluff in Hell Hollow. He drove a small hand pick into the face just below the traces of lignite. Out fell a crumbling of clay, pieces of what is called the boundary layer. This layer, just a few inches thick, is the zone of contention in a rattling debate among geologists and paleontologists. At issue are the agents of mass extinction of life on earth and, not least, the ultimate fate of the dinosaurs. Did the world of these wondrous creatures end in a bang or a whimper? Many geologists believe the earth was blasted by an asteroid 65 million years ago, about the time the dinosaurs vanished. Such a catastrophic visitation from outer space could have done in the dinosaurs as well as perhaps 50 percent of all life, large and small, marine and terrestrial.