Hundreds of New York University graduate assistants forsook the classroom for the picket line Tuesday, after a last ditch effort Monday by a delegation of faculty members failed to persuade NYU's president to recognize the graduate student union.

The strike is the culmination of tensions that began this summer when NYU announced it would no longer recognize the Graduate Student Organizing Committee, the local affiliate of the United Auto Workers that represents NYU graduate assistants.

The university was not sure yesterday exactly how many courses would be affected, but John Beckman, a spokesman for NYU, called the impact "minimal." He said that, of the 2,700 classes taught on any given day, 165 are led by graduate students. Many more classes, however, use graduate students to help in some capacity, and, since NYU has decided not to look for replacement labor so far, professors will have to decide individually how to handle classes.

Outside, however, in front of Bobst Library, the disturbance was anything but minimal. A 12-foot inflatable rat stared into Washington Square Park and, at any particular moment, scores to hundreds of graduate and undergraduate students, staff and faculty members, and miscellaneous supporters marched back and forth, bearing signs like "Nerds on Strike," and "NYU=Walmart?" Befitting an activity in Greenwich Village, protesters kept a carefully coordinated beat of drumming -- buckets, water cooler bottles and actual drums -- and whistle tooting, with the occasional NYPD siren adding a techno air to the protest.

To show their support, or at least their unwillingness to cross the picket line, more than 400 faculty members, according to GSOC, have moved or are looking to move classes off campus. Based on majority votes, 19 departments and the entire Tisch School of the Arts passed resolutions that varied from urging NYU to recognize the union, to promising not to give bad evaluations to graduate assistants who strike.

Sukhdev Sandhu, an English professor, moved his Intro to Asian American Literature course to Under St. Marks, a basement blackbox more befitting a rookie indie rocker than a discussion of Amy Tan's use of italics in The Joy Luck Club. Nonetheless, there two dozen undergraduates were as their professor sat on stage atop a black box, looking through black-rimmed glasses, wearing black pants and a black jacket, the only bit of color a purple GSOC pin on his jacket breast. Starting next week, Sandhu will hold class at the KGB Bar, near campus, and told students to prepared for that venue "for the remainder of the semester." He later added, with a laugh, that "as a frequent drinker there, it's nice to be there in another context."

At Under St. Marks, every now and again, a student would exit stage right to use the bathroom. Sandhu did not seem to mind the setting at all. "This is how I think all student life should be," he said of the group of students congregated on a street corner on a crisp fall day before class. None of Sandhu's students seemed to mind the alternate location too much, though some said that scheduling was getting crazy as courses were sprinkled around Manhattan. One freshman in the class said he had to rush across several Manhattan miles to reach his Socialist Theory class, a lecture that had been relocated to the New York Marxist School, on West 27th Street.

Beckman said that NYU allows faculty members some discretion in conducting their courses, but said that faculty members are encouraged to make scheduling as easy as possible for students. He noted that many graduate assistants are continuing to teach "either because they disagree with the union, or because they feel a sense of responsibility to students," he said. So far, NYU has not made plans to dock pay or to bring in replacement labor.

"We're not there yet, and I think everyone hopes we won't get there," Beckman said.

Elizabeth Loeb, a law and society doctoral student who was at NYU before the first contract, said that life is much better with the union because it allows grad students to file grievances with someone other than their bosses. She said she is prepared to stay on strike "until we get a second contract," and said the undergraduates she was teaching said they "are proud of me." Loeb and other graduate students on strike, or in support of the strike, said she would only attend courses that she is enrolled in if they've been moved off campus.

At least dozens of undergraduates showed up at the picket line throughout the day to support the strike.

Brendan McCarthy, a sophomore film major who, like many on the picket line, was sporting a yellow arm band, and said that he would "look for a new institution" if the union was not recognized by the end of the year. "I offered my apartment as a classroom to one teacher," McCarthy said, adding that the teacher did not want to move class and declined the offer indignantly.

Some professors who joined the picket line explained the controversy to passersby who gawked at the train of people snaking around Washington Square Park shortly after noon. Some of those professors talked about what they called a misleading letter sent by John Sexton, NYU's president, to the parents of undergraduates. In the letter, Sexton noted that the average annual aid package given to doctoral students is $50,000. Faculty members, on the sidewalk and in an open letter, disputed that, noting that the typical stipend is $19,000, and the rest is tuition remission and benefits.

In 2002, GSOC became the first recognized union at a private institution, and graduate assistants say that the resulting contract brought a better quality of life. The university, however, contended that the union was interfering with academic decisions, and said that GSOC had done good things, but was no longer needed.

Sexton asked graduate assistants to have faith that the university would continue to foster a good relationship. But graduate assistants say that, though they got an initial raise, their health benefits were slashed --  a comparison of this year and last is on the GSOC Web site -- soon after NYU refused to negotiate with the union, and they are not willing to trust their fate to NYU. (Beckman, of NYU, said that the university is continuing to pay full premium costs for graduate students, but that -- as in past years under the contract -- rising health care costs periodically result in changes in coverage levels.)

Neither GSOC nor NYU have any idea when the current game of chicken will end. Said Beckman in an e-mail, "certainly, any consequences would be consistent with our view of [graduate assistants] as students whom we value greatly as important members of our community."