In a large classroom on Tuesday afternoon 32 students listened to headphones while their teacher eagerly tried to explain to them all the details of the American congressional lobby and special interest organizations.

But this was no ordinary summer school class. The "students" were members of the Duma, the lower house of the Russian Parliament, and the "teacher" was John L. Zorack. a professional lobbyist.

The headphones provided an in-progress translation to both Zorak and the Duma members. While the Russians heard the lecture in their native tongue, Zorack was able to hear their questions in English.

Mikhail A. Mitiukov, the first deputy chair of the Duma, said a "positive aspect of the program is that the Duma representatives have a chance to speak out about what they're doing back home and to compare the two systems."

The Duma's members are participating in a 10 day program at Harvard University's John F. Kennedy School of Government. This year's program, a continuation of last year's curriculum, explores the role of both national and state legislatures in a democracy.

Zorack used the words of Leo Tolstoy to help convey the intricacies of the American system to his Russian students.

"Tolstoy said that laws and institutions gravitate like clocks; they must be occasionally cleaned, checked, and set to time," Zorack said. "In the U.S. it's the same."

Zorak ended his lecture by addressing the Russians in their own language and expressing his wish 'that they will take back at least one or two hints about the American system to their country."

Zorak's class is just one of the intense schedule of courses that will explain the American system of government through a series of guest lecturers and field trips.

The list of lecturers includes several Harvard professors, as well as a number of government officials like former Massachusetts governor Michael s. Dukakis.

The field trips have taken the Duma members to a red Sox Baseball Game, the house of Boston Mayor Thomas M. Menino, the Statehouse and even a small town meeting in Concord.

The program will end on July 29 with a final class on U.S. and Russian relations. It will sum up the 10-day curriculum and encourage future relations between the two nations. The class will be taught by Robert D. Blackwill, the faculty chair of the program.

Although not every part of the rigorous schedule has been enthusiastically received, Duma members say they are pleased with the program in general.

"We take a realistic stand and realize that not everything done here can be taken as a whole and used," Mitiukov said. "Any kind of experience here is a good one."