When Jean Yang ’08 arrived at Harvard in the fall of 2004, she was in many ways a typical, undecided freshman, contemplating concentrations ranging from economics to biology.

But after enrolling in CS50, Harvard’s introductory computer science class, she instantly developed a passion for the subject.

Yet in Yang’s early semesters of studying computer science, she faced challenges that she never expected. Having graduated from an all-girls high school, she was surprised to find herself in classes with fewer than 10 women, and she struggled with the persistent sense that she was unwelcome or unqualified.

“When you’re an undergraduate woman, and you don’t have a ton of self-confidence, you’re going to have to really assert yourself in a field where you’re being treated by others as if you don’t know anything,” Yang said.

Despite these difficulties, Yang decided to concentrate in computer science, and after graduating Magna Cum Laude in 2008, she is now pursuing her computer science Ph.D. at MIT.

But as some women interested in CS face similar challenges, few remain in the field long enough to experience the same success.

In fact, computer science is the most gender-skewed concentration offered at Harvard, with women comprising only 13 percent of undergraduate CS majors.

The proportion of female CS majors is similar at some of Harvard’s peer institutions—including Princeton, where it stands at 19 percent, and Stanford, where it is 14 percent.

But interviews with over a dozen women involved with computer science revealed no clear consensus on the issue. While some believe this disparity is due to the difficulties faced by female CS concentrators at Harvard, others say that they have found a welcoming environment in Harvard CS and ascribe the variance to experiences that women face prior to college.

AN INVERSE RELATIONSHIP

According to statistics provided by the School of Engineering and Applied Sciences, the gender imbalance within CS classes seems to grow with each subsequent course on the CS track.

While 34 percent of students in CS50 were female when the class was offered last fall, female enrollment in CS51 and CS61—the two classes that typically follow CS50—are 25 percent and 23 percent, respectively.

By the time students reach CS124, a class that usually comes later in the track, female enrollment drops to 18 percent.

Women are also more likely to concentrate in another coding-heavy field or to minor in CS than they are to actually concentrate in the subject.

According to data collected from the Registrar’s Office, 43 percent of students concentrating in Applied Math: Computer Science are female, 36 percent of students concentrating in the Electrical Engineering and Computer Science track of the Engineering Sciences degree are female, and 25 percent of students pursuing a CS minor are female.