About 28 percent of all Brown graduate students work as teaching assistants, says Virginia Baxter, an official in the graduate school department.

"Brown is very proud of our Center for the Advancement of College Teaching. The program basically teaches our graduate students how to teach," says Bernard Bruce, associate dean of the Graduate School of Arts and Sciences.

Isabel Gardner, assistant dean of Cornell graduate school, says, "a Graduate School Committee functions to address any concerns voiced by the T.A.'s, but we don't have a union. There haven't been any specific complaints over salaries or benefits, but of course we would all like to see them paid more."

About 25 percent, or 1500, of Cornell's graduate students teach approximately one course per semester and receive a basic stipend of $6400, plus a tuition benefit, Gardner says.

At MIT, T.A.'s are paid full tuition and they receive an average monthly salary of $360.

Most of MIT's graduate students teach before taking their general exams, after which they become research assistants for professors. Since most people write their dissertations on the topic for which they are research assistants, this helps them in the long run, says Jeffrey Meredith, president of the Graduate Student Council.

The T.A.'s responsibilities range from teaching sections and doing grading to giving actual lectures. "Some faculty leave the real teaching to the T.A.'s and come in only for lectures they can do off the top of their head," Meredith says.