"[A]s programming enjoyed its first burst of cultural attention, so many students were racing to enroll in computer science that universities ran into a supply problem: They didn’t have enough professors to teach everyone. Some added hurdles, courses that students had to pass before they could be accepted into the computer-science major. Punishing workloads and classes that covered the material at a lightning pace weeded out those who didn’t get it immediately. All this fostered an environment in which the students mostly likely to get through were those who had already been exposed to coding — young men, mostly. “Every time the field has instituted these filters on the front end, that’s had the effect of reducing the participation of women in particular,” says Eric S. Roberts, a longtime professor of computer science, now at Reed College, who first studied this problem and called it the “capacity crisis.”"