19.8%: What the Campus Sexual Assault Study Actually Measured
November 5, 2026 · Frisian News
Photo: Wikimedia Commons
The 'one in five' campus assault statistic comes from a 2007 survey of two universities with a 42% response rate. Lead author Christopher Krebs says it is inappropriate to use it as a national baseline.
One figure has anchored a decade of campus-safety policy in the United States: one in five women at American colleges has been sexually assaulted. That figure traces back to a single 2007 study by researchers at RTI International, funded by the US Department of Justice's National Institute of Justice under grant 2004-WG-BX-0010. The study's own lead author now says the number is being misused.
The Campus Sexual Assault Study, authored by Christopher Krebs, Christine Lindquist, and colleagues, surveyed undergraduate women at exactly two large public universities, one in the South and one in the Midwest. Of the randomly sampled women contacted, 5,446 completed the web survey. The response rate was 42%, meaning roughly six in ten women contacted did not participate.
That sample is the entire empirical base for the 1-in-5 claim. RTI International received funding from the National Institute of Justice to document the prevalence of sexual assault "among a large sample of undergraduate women from two large universities," according to the study's final report, 110 pages long, catalogued under NCJ number 221153.
Writing in Time, Krebs and co-author Lindquist stated clearly: "the 1-in-5 statistic is not a nationally representative estimate of the prevalence of sexual assault, and we have never presented it as being representative of anything other than the population of senior undergraduate women at the two universities where data were collected." They added that "there are caveats that make it inappropriate to use the 1-in-5 number in the way it's being used today, as a baseline or the only statistic when discussing our country's problem with rape and sexual assault on campus."
The 19.8% figure is also not a rape rate. The CSA Study defines sexual assault broadly to include forced kissing and unwanted groping, acts the authors classify as sexual battery. When restricted to rape, meaning unwanted sexual penetration, the prevalence among senior undergraduate women at those two campuses drops to 14.3%, or 1 in 7. Krebs and Lindquist acknowledged that distinction themselves in the same Time piece.
The statistic also applies only to seniors who completed the survey, not all enrolled women. Among all undergraduate women across every year of study, the final report's data highlights put completed sexual assault since entering college at 13.7%. That figure is different again from the senior-year 19.8% that became the headline number.
The 42% response rate introduces a further limitation the authors acknowledged directly. They ran a nonresponse analysis and found no significant difference between respondents and non-respondents by age, race or year of study. Even so, they wrote, "it is possible that nonresponse bias had an impact on our prevalence estimates, positive or negative. We simply have no way of knowing whether sexual-assault victims were more or less likely to participate in our study."
None of this means campus sexual assault is not a serious problem. The two-campus numbers the CSA Study produced are real, and Krebs and Lindquist stand behind their data. Researchers who spoke directly with Krebs noted that among the women in the survey who reported unwanted sexual contact, most had experienced rape, oral, vaginal, or anal, not merely other forms of unwanted touching. That matters.
A two-campus web survey with a 42% response rate does not describe what happens at thousands of colleges across the United States, and the researcher who ran it said exactly that on the record.
Published November 5, 2026 · Frisian News