Whether rape happens on U.S. college campuses at rates similar to elsewhere in America or to rates in Tanzania and South Africa has been a major subject of dispute recently. Folks from President Obama to swearing 5-year-olds princesses have been citing a statistic that 20 percent of women on college campuses, or one in five, will be sexually assaulted while there—a stat that has also been routinely debunked. However, a new sexual assault survey from the Massachusetts Institute of Technology (MIT)—one of the first schools to release broad data on campus sex crimes—seems to corroborate everyone’s favorite sketchy stat.
Or does it? Media are reporting that one in six female undergraduates at MIT have been sexually assaulted (with this translating in some headlines and social media shares to “one in six have been raped”). But the MIT survey suffers from the same issues that plague previous studies on campus sexual assault.
First, the survey’s methodology: In April, MIT emailed its sexual assault survey to all 10,831 undergraduates and graduate students. Students could then opt to take the survey or not. Ultimately, 35 percent of MIT students did. But whenever you have an opt-in survey, those who self-select to take it are not necessarily representative of a given population. Or, as MIT researchers put it, “response bias is expected in virtually any voluntary survey, particularly one focused on a narrow topic. … the rates based on those who responded to the survey cannot be extrapolated to the MIT student population as a whole.”