Yick Chan, a graduate student from Hong Kong, says she works hard to explain complex lessons to her Physics 1 sections.

Although most students seem to grasp the information, she says a few do not. And without asking her for further assistance, they simply transfer out of her section.

"They won't try to ask me questions at all," says Chan, who says some students judge her unfairly. "They think, 'She's not supposed to understand,' and they go to the Physics office and complain and ask to be switched. They won't try to understand."

Some students, Chan says, do not believe a foreign teaching fellow can be a competent teacher, but she stresses that only a small group of students hold this opinion.

Chan's story reflects a national phenomenon. Foreign graduate students are more and more often teaching American youths, sometimes resulting in misunderstanding and tension.

From 1980 to 1990, students from other countries receiving doctorates from American schools almost doubled, the rate increasing from 12.8 percent to 23.4 percent.

Many of those foreign students work as teaching fellows, at Harvard and at other universities, and some undergraduates complain of difficult accents and styles of teaching.

Brandon C. Gregoire '95, co-chair of the Undergraduate Council's Academics Committee, says he has heard such complaints from Harvard undergraduates.

I have had students come to me to express at the way they [foreign teaching fellows] enunciate their words," Gregoire said.

But the difficulties fall on both sides, according to James Wilkinson, director of the Bok Center for Teaching and Learning. As Chan's story illustrate's, sometime's students are unwilling to give teachers from other nations a chance.

"I think it's a shared problem," he says. Some American students definitely demonstrate xenophobia he says, and sometimes even race-based prejudice.

"I think it would be foolish to ignore the fact this does exist," he says.

Virginia Maurer, who directs the Bok Center's English as a Second language program, says she sees such bias as well.

"I do think there is an element of that," she says. "I don't know how much at Harvard."

Wilkinson stresses that the problems are not all the undergraduates' fault.

He says teaching fellows from other countries sometimes do have difficulties with English, and American students often exhibit different behavior in class than they are used to.

"I come from a very different educational system," says physics graduate student Iuliana who is from Romania. "Everyone is very conservative, usually students don't speak so much."

But Wilkinson says at Harvard such barriers do not truly make a huge difference in teaching fellows' ability in the classroom.

"It's really mixed," he says. "There are some that have low CUE ratings."

But of the approximately 30 teaching fellows who rank below a 2.8 on the CUE scale, the majority are American born, he says, and foreign born graduate students are not on that list disproportionately to their numbers in the ranks of teaching fellows.

Wilkinson says he hopes the Bok Center's efforts can help alleviate the foreign students' difficulties through training and evaluations. Over half of the foreign born teaching fellows come to the Bok Center, he estimates.

"By and large, the foreign teaching fellows are trying very hard," he says.

Student preconceptions are a difficult and complex "educational issue," he says, and "it's something we're just beginning to understand belongs on the educational agenda.