But the varying demand for TF's throughout the university seems to be the determining factor in how heavily certain grad students must work, and how selective professors can be in choosing their staffs.

Verba says that "we look for an ability to organize, communicate, and a good knowledge of the subject matter" in the selection of TF's; McWade cites their grades and academic qualifications as other important criteria.

But Edward L. Keenan '57, dean of the Graduate School, is more realistic. "It's a matter of supply and demand" in various departments, Keenan says, noting that each department has its own rules for selecting and evaluating TF's.

Margaret M. Gullette, assistant director of the Harvard-Danforth Center for Teaching and Learning, says that for the Faculty as a whole, more TF spaces exist than applicants to fill them.

Verba concedes that except for obvious exceptions--grad students with poor English, severe nervousness, or poor communicative ability--this shortage means that nearly any student who wants to teach a section gets to. "We can't pick them by how good of a teacher they are, because they don't have any experience," he says.

Given that a certain number of TF's will prove to be peer instructors. Verba has promoted departmental evaluations, regular use of the Danforth Center, and more interaction between professors and TF's as methods of improving teaching quality.

Students have a chance to rate their section leaders in each course during the CUE evaluation, the College conducts each semester.

Those TF's receiving an average rating of 6-0 or better (on a scale of 1 to 7) get a Certificate of Distinction Last year Verba's office gave out 100 certificates to the approximately 900 TF's.

Verba pays closer attention to those who score at the other end of the scale. He chooses 35 to 40. TF's with "disaster ratings" each semester, recommending that they get extra instruction either from the Danforth Center or the summer school's course of English as a second language.

The Graduate School pays for half the costs of the Danforth Center, Keenan says, in order to expose interested section leaders to videotaping critiques, and seminars designed to impart the fundamentals of teaching itself.

Approximately 250 grad students come to use the center voluntarily each year, according to Gullette.

McWade says that while the TF program has an implicit assumption that all grad students can teach, many need to use devices like the Danforth Center to bring out this potential.

"In the Ph.D. program, we assume they're smart and have the ability to communicate," she says. "But there are a lot of very, very bright people here who don't necessarily have the innate skills to make themselves understood."

Other methods of helping these students rely on increased communication between TF's, students, and professors Verba has created a "lunch fund" for course heads to use for hosting regular meetings of TF's to discuss student problems. Rosovsky's recent report urged professors to teach sections themselves and conduct mid-course evaluations to better appreciate the problem facing TF's Gullette tells students with specific complaints about TF's to raise the issue with their professor.

Verba and Rosovsky agree with her that the ultimate responsibility for the system rests with the professors who supervise individual TF's.