"It's a hell of a lot of responsibility," Sandik says.

Walfish also says that undergraduate TFs put a tremendous amount of energy into answering questions by e-mail, preparing assignments, grading, holding office hours and performing other general duties.

Caywood says that teaching for a computer science section is as much work taking a fifth course, and Sandik says she spends hours creating lesson plans.

"I spent a lot of time coming up with creative ways [to teach] and since I'd taken the class I knew what was a good way to present the material and what was a not-so-good way," she says.

Yagan, who says proximity to his students motivates him to do a good job, says, "There can be more pressure on an undergraduate TF."

"It makes me prepare for sections more thoroughly. It makes me feel like there's a real need to perform well," he says.

Still, Lori J. Park '96-'97, who was also a TF for CS-50 last semester, says being an undergraduate TF sometimes disrupted her life because students had fewer qualms about calling her at any hour than if she were a graduate student.

Gender Balance?

Undergraduate TFs interviewed acknowledged a striking gender imbalance among their peers.

Last semester, only about one-fifth of the CS-50 TFs were women. This semester, of the 12 TFs for CS-51, only one is a woman, according to Yagan.

Yagan, Walfish and many others interviewed, however, say the gender imbalance among undergraduate TFs reflects the low numbers of women in the sciences.

"Certainly, given that most of the TF positions for undergraduates are in the sciences and fewer women are in the sciences, you're going to have [an imbalance]. The TF representation is proportional to the number of male and female concentrators [in the sciences]," Walfish says.

"Obviously, there should be more female TFs," he adds.

Mueller agrees that the gender imbalance is a symptom of a problem endemic to the sciences, and not specific to undergraduate teaching fellows.

"I think the gender imbalance [in student TFs] reflects the gender imbalance within the Chemistry department rather than any bias," Mueller says.

Park, one of the few female TFs in CS-50 last semester, says she sees a need for female role models in computer science.

"I've had lots of women call me up and I've have numerous women write to me and ask me if they should take computer science...I think a lot of women feel more comfortable talking to me than to their other [male] TFs," Park adds