August 16, 1983

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.