Four weeks into the semester, a section leader for Applied Sciences 10, "Introduction to Programming" conducted an informal poll of his students, most of whom knew his Lowell House address and telephone number.

"I went around the room and said, 'How old am I?" says David A. Epstein '83, and the average age was 24. But if they were going to think I was a tutor, that was okay."

Asked recently if there were any difficulties with having undergraduates as his teaching fellows for Mathematics Ar. Precalculus Mathematics", Joseph F. McCafferty Jr. '86 replied, "No they're not--oh, they are?"

The persistent shortage of graduate students in the natural sciences annually results in the presence of undergraduates in the classroom--behind the lectern. They appear most frequently in introductory computer science and mathematics courses like AS 10 and Math Ar. as well as Biology 7, "Introductory Biology" and several intermediate level Applied Mathematics courses.

Undergraduates have the same responsibilities as graduate students who lead sections, ranging from complete control over sections of Quantitative Reasoning A and Math Ar. to leading lab sections of Bio 7, to reviewing problem sets for computer science courses.

Most people involved with undergraduate section leader report that the system works out to the benefit of all, provided the material presented is sufficiently limited to an introductory level and the undergraduate is able to strike a balance between being a friend and being an authority figure.

Jonathan A Epstein '83 calls the peer relationship he has built up with the section of Math At he teaches, "at once the biggest problem and the biggest asset it's hard to pretend that you're the one in charge.

Sidney Verba, associate dean for Undergraduate education calls the selection and supervision of undergraduates as teaching assistants extremely tightly controlled the people I know who use undergraduates run a very tight ship.

The most careful selection process is for QRA and Math Ar. "It's very complicated." says Deborah J. Hughes-Hallett, senior preceptor in Mathematics, who heads both courses.

Twice a year, Hughes-Hallett stages a campus wide publicity campaign encouraging interested juniors and seniors--sophomores are "extremely rare"--who have completed Math 21, AM 21, or an equivalent course to sign up for interviews.

The selection process involves meetings with Hughes-Hallett and with two current teaching fellows, as well as videotaping a five minute sample lecture that Hughes-Hallett says she "watches and reviews a couple of times."

This year--the course's 11th the procedure yielded 14 undergraduates out of 18 teaching fellows, a percentage Hughes-Hallett calls typical.

Teaching fellows in both offerings supervise every aspect of the course, including grading and the order in which topics are covered.

Charles S. Boulas '83 is teaching QRA for the second time and also taught Math Ar last fall. He admits, "It might be a tough situation to teach a peer," but adds, "it's something that most students take to very well."

Boulas starts off by letting his sections know he is an undergraduate. The first day of class I tell them who I am and tell them a little about myself," he says, adding that students usually accept him as an instructor quickly.