Since the risk of assault is higher for students living on campus, the 0.6% reported assault rate is lower than rates reported for campus environments.In 2007 the National Institute of Justice funded the Campus Sexual Assault (CSA) survey, a web-based survey of 6,800 undergraduates at two large universities using multiple explicitly worded questions about sexual victimization.
Schools that participated in the survey included: Caltech, Texas A&M, Iowa State, University of Texas, Case Western, University of Florida, University of Pittsburg, Purdue University, University of Arizona, Columbia University, Cornell University, Washington U. Louis, Ohio State, University of Minnesota, University of North Carolina, University of Oregon, University of Virginia, Brown University, Michigan State University, Harvard, University of Missouri, University of Pennsylvania, Dartmouth College, University of Wisconsin, Yale University, University of Southern California, and University of Michigan.
It found that more than 20% of female and 5% of male undergraduates said that they were victims of non-consensual sexual contact, defined as behaviors ranging from unwanted sexual touching or kissing to penetration, through either physical force or incapacitation, since entering college. While they noted that low response rates were only an indirect indicator of the reliability of the results, they found evidence that their estimates of sexual assaults may have been biased upward because respondents were more likely to have been assaulted than non-respondents.
A 2014 assessment by Sinozich and Langton used longitudinal data from the NCVS to measure rape and sexual assault among college aged U. The study also found that college aged women (regardless of enrollment status) were assaulted at a significantly higher rate than non-college age women, 4.3 per 1,000 (0.4%) per year versus 1.4 per 1,000 (0.1%) per year, but that women who were not enrolled in college were 1.2 times more likely to be assaulted than college aged women who were enrolled.
The NCVS is one of the few national level, longitudinal sources of data on rape and sexual assault, and it has a relatively high response rate (88%) compared to other studies of sexual victimization.
However, Christopher Krebs, the lead author of the CSA, cautions that the results from these two schools in no way nationally representative, noting, in a conversation with one reporter: "We don’t think one in five is a nationally representative statistic.” and “In no way does that make our results nationally representative.".
In a follow-up study in 2008, the authors of the 2007 Campus Sexual Assault Survey examined sexual violence experiences at historically black colleges and universities (HBCUs).
Although survivors of sexual violence suffer psychological consequences, they may reason that the costs of reporting—e.g., loss of privacy, humiliation, having to testify to police or at a college disciplinary hearing—outweigh any potential benefits.
Women of minorities, women who are raped by an acquaintance or family members, and women who were using drugs or alcohol when they were assaulted, are generally less likely to report the crime to police.
Data is collected using telephone interviews, which permits clarifying questions, and uses a bounded time frame of six months, limiting the likelihood that results are overestimated due to "telescoping" (the reporting of events occurring outside of a reference period as though they occurred within the specified period).
However, results reported by the NCVS are consistently lower than studies using other methodologies.
Diane Follingstad, Director of the Center for Research on Violence Against Women at UK, said that volunteered data is not always representative.