Reinventing CS50

Abstract

Computer Science 50 is Harvard College’s introductory course for majors and non-majors alike, enrollment in which both rose and fell along with the dotcoms. Although enrollment peaked in 1996 at 386 students, it had settled by 2002 in the neighborhood of 100. We set out in 2007 to combat that trend by tackling two problems. We hypothesized that CS50 suffered from two, one of perception and one of design. Although, per end-of-term surveys, the course had never lacked for good teachers or good content, the consensus on campus for years had been to beware this particular course. And the course’s own syllabus may very well have been dated in the eyes of students who had begun to carry regularly modern hardware and software in their backpacks and pockets. Not only did we proceed to revamp every one of CS50’s problem sets, we brought its syllabus more in line with technological trends already familiar to students. And we altered the tone of the course to appeal to those “less comfortable” with computing on campus. But we took care to preserve the course’s rigor and underlying fundamentals, lest we do our own students a disservice. Our new approach appears to be working. Between 2006 and 2007, enrollment in CS50 more than doubled from 132 to 282 (+114%). Between 2007 and 2008, enrollment increased another 17% to 330, though even more striking was that year’s 48% increase in female enrollment. By 2009, enrollment remained strong at 338. We present in this work what we have done and why we have done it.