CHAUTAUQUA, N.Y. -- The senior Soviet Communist Party official seemed somewhat taken aback when the precocious young American bounced up to his table and announced: "Hi, my name is Donna, and I'm your waitress for today." After shifting uncomfortably in his chair, he finally replied in thickly accented English: "My name is Dimitri, and I'm from the Soviet Union."

East and West met each other in some unexpected ways last week at this Victorian-era lakeside resort-cum-intellectual holiday camp, scene of the third annual "citizens' summit" on U.S.-Soviet relations. But, despite the good will generated by the Kremlin's new policy of glasnost or openness, the psychological and political gulf between the two sides seemed almost as wide as ever.

The six-day conference, which ended yesterday, witnessed many warm personal encounters between the 250 or so Soviet visitors and their American hosts. But it was also notable for the heated arguments that broke out as soon as the conversation turned to politics or human rights. And there were many reminders that the word "democracy" has different connotations in English and Russian.

While the carefully selected Soviet contingent came to Chautauqua singing the same tune of praise for glasnost, the American side spoke in a cacophony of voices. Vigorous defense of official U.S. policies from such administration spokesman as Deputy Secretary of State John Whitehead alternated with criticism of President Reagan from ordinary American citizens worried about international tension.

The atmosphere of one-sided give-and-take prompted one Soviet official to retell an old joke about the American who boasts that he is so free, he can stand outside the White House and shout "Down with Reagan," to which the Soviet citizen retorts: "So what, I can stand outside the Kremlin and shout the same thing."

The Soviets got a glimpse of glasnost American-style when Reagan's senior adviser on Soviet affairs, Fritz Ermarth, defended U.S. support for the Nicaragua contras and was roundly booed by Americans in the audience. A few moments later, many of the same people jeered Oleg Sokolov, minister-counselor at the Soviet Embassy in Washington, when he sought to justify his country's invasion of Afghanistan.

The psychological divide extended to such nonpolitical areas as a roundtable on the Soviet theater. A Soviet interpreter was stumped for words when an American asked whether there was censorship of "bedroom scenes" in the Soviet Union. As an American specialist in the Soviet theater remarked: "He can't translate the phrase because the concept just doesn't exist in Russia."

Nonetheless, for the Soviet participants, Chautauqua must have been reassuringly like home. Set in woods on the edge of a lake and surrounded by a fence, this 19th-century resort could almost pass for a privileged holiday retreat in the Soviet Union. Alcohol is banned, cars are discouraged, and uplifting activities such as lectures and concerts are organized for vacationers by the paternalistic Chautauqua Institution.

Substitute Communist Party halls for the churches that dot the grounds, and the participants in this week's Third General Chautauqua Conference on U.S.-Soviet Relations could have been back in the U.S.S.R.

The "Chautauqua process," as it has been dubbed by its promotors, began here in 1984 and was attended by several dozen American and Soviet officials and journalists. It continued last year in the Soviet Union in the Latvian town of Jurmala but was sidetracked by harsh recriminations over the arrest of U.S. journalist Nicholas Daniloff by the KGB, the Soviet secret police.

This year's conference coincided with a new thaw in relations between the superpowers as they move toward an agreement on eliminating intermediate-range nuclear weapons, and it was described by organizers as the biggest and most successful yet. The Soviet delegation, headed by cosmonaut Valentina Tereshkova, included one of the Kremlin's chief arms negotiators, Col. Gen. Nikolai Chervov, and eminent scientists such as Roald Sagdeev, head of the Soviet space program.

U.S. participants included New York Gov. Mario M. Cuomo, Sen. Bill Bradley (D-N.J.), and singer John Denver.

The discussion on U.S.-Soviet relations took place in front of a kind of Greek chorus of elderly women who form a significant proportion of Chautauqua residents. Clutching seat cushions and dressed in sensible clothes, they trooped from seminar to round table to concert, displaying an apparently insatiable appetite for knowledge about the other superpower.

To make this a "citizens' summit," the Soviets included roughly 200 "ordinary" citizens in their delegation. The Soviet moderator of a human-rights seminar called upon one such "loyal citizen" to comment on allegations about the harassment of human rights activists in Latvia. He turned out to be president of the Latvian Supreme Court.

The discrepancy in the makeup of the two delegations raises the question of what each country achieves by "citizens' diplomacy."

The Soviet answer was supplied by Vladimir Posner, the ubiquitous television commentator, who noted that Chautauqua-style conferences are an opportunity to influence public opinion. According to this view, it becomes more difficult for U.S. politicians to depict the Soviet Union as an "evil empire" if ordinary American voters have met a Russian and found him to be peace-loving.

Potential U.S. gains are more complex, according to American participants in this year's conference. Opinions expressed at Chautauqua filter back to the Soviet Union via television and radio broadcasts, but the link between Soviet public opinion and Soviet foreign policy is not as direct as in the United States. More important is the opportunity to expose members of the Soviet elite to a free and pluralistic society.

By the end of the Chautauqua meeting, Gen. Chervov had been confronted with a young Soviet defector from Afghanistan; Elizabeth Condon, who has been waiting eight years for her Soviet fiancee to be allowed to emigrate, got a chance to lobby Soviet foreign ministry officials; Leonid Dobrokhotov, a Communist Party official, had heard countless complaints about the Soviet invasion in Afghanistan and Czechoslovakia; and Vladimir Posner had agreed to exchange newspaper columns with Jack Anderson.