A rare survey of Polish public opinion indicates that many Poles believe their country has taken a historic turn and that the reforms promised by the country's rulers will largely be realized and will make a difference in their lives.

The survey, published in the respected Polish weekly, Polityka, is remarkable not only because such public sampling is virtually unknown in Communist-ruled countries but also for the hope it reflects in a nation where cynicism and mistrust of authority run deep.

Casual interviews with several Poles in recent days affirm the view reflected in the Polityka survey that the course of Polish history was altered by the pressure of the workers' strikes and that the immediate future is likely to bring some improvement.

The Polityka survey was conducted on Sept. 4 and 5, several days after the signing in Gdansk and Szczecin of agreements that ended the major shipyard strikes, but just before the ousting of Edward Gierek as Poland's Communist Party chief.

Included in the sample are 500 people from a wide cross section of job and educational backgrounds, although for practical reasons the poll was limited to those who work in large institutions and enterprises in leading industrial areas of Poland. Not included are farmers, pensioners, nonworkers, people in small towns and those employed in small businesses.

Asked what effect they thought "recent developments" would have on a list of things in the next three years, the greatest number of people said they were optimistic that the "level of society's consciousness" would show improvement.

More than 70 percent of those surveyed said they expected better church-state relations, more participation by the public in important decision-making, and greater worker self-government.

In view of the Warsaw government's pledge to relax censorship as well as to publish more information about Poland's economic situation, two out of three said they expected improvement in "the reliability of information."

Publication of the poll itself was an indication of the greater freedom the Polish press is enjoying. Some polling was done in the past, a spokesman for Polityka said, but none had been commissioned in the last five years because of limits imposed by government censors.

While shortages of all kinds have become a standard feature of Polish life, 70 percent of those polled by Polityka sounded optimistic that food supplies would increase soon. There was slightly less optimism about boosting the supply of industrial products and still less hope for shortening the wait for an apartment.

More pessimism than optimism was voiced on the future condition of Poland's "external security" -- a delicately worded phrase intended to reflect Polish concern that the Soviet Union may eventually intervene to squelch reforms under way.

One interesting sidelight to the survey is that through the generally optimistic public mood runs a sketicism among those with the highest education. o

This group consistently responded more pessimistically to the chances of improvement in every concern raised in the survey.

Asked to name the recent event in Poland of greatest importance, the majority pointed to the government's promise to allow independent trade unions -- a key demand of the strikers.

Questioned on why they thought the worker revolt took place, the majority of those surveyed saw the protest as the "unavoidable consequence of existing policy." Virtually none of those polled said they believed the labor trouble was "mainly the effect of antisocialist and anarchic forces" -- a favorite doctrinaire interpretation.

My own interviews with Poles on the sidewalk and in Warsaw restaurants affirm many of the views in the Polityka survey.

A group of metal workers in Warsaw's old town square, here on paid holiday for donating blood, talked of definite change.

"For the first time, we were able to express ourselves honestly," one said.

Lunching nearby, a well-dressed couple, both employed by Warsaw city transportation division, noted how much more interesting and informative the daily press has become.

The word "strike" is now taken as a matter of course in papers where a short time ago it had not been allowed to appear; the extent of Poland's indebtedness is written about more openly; and the development of the independent trade union movement is an unavoidable press feature, although critics still charge that coverage of this and other issues remains sorely incomplete.

A 35-year-old economics professor, walking with a friend, observed that what happened in Poland was the function of historical destiny.

"It was only a matter of time before something like it happened," he said. "There's been a history here of growing awarenesss of people of their power."

Through all these remarks runs the thought that a different Poland exists now than before July 1980, when the strikes and unrest began. But this attitude is laced with a strong dose of caution, the product of a heavy cynicism accreted over two generations of unfulfilled government pledges.

"We have too little time to get involved in political analysis," said a 30-year-old draftsman from Bialystok on vacation here, echoing a prevalent Polish attitude. "We will just wait and see."

He added something that goes to the root of much of the reservation about the future that is felt here.

"Everyone is afraid the Russians will stop the process," he said. "Everyone believes that during Gierek's time, the Russians were influencing the decisions. Maybe that wasn't ture, but everyone feels so, and they are still worrying."