Why some studies make campus rape look like an epidemic while others say it's rare

One of the most alarming things about sexual assault on college campuses is how little we know about it. Is there really an epidemic of campus sexual assault? Or are college-age women just at a risky point in their lifetime, regardless of their campus environment?

New data from the Bureau of Justice Statistics seems to suggest the latter. The National Crime Victimization Survey, which asks about reported and unreported crimes Americans experienced in the past year, found that there were 6.1 rapes per 1,000 female students each year between 1995 and 2013. This is slightly less than the figures found for non-college students in the same age group. And it's much less frequent than other often cited statistics on the prevalence of rape in college: that 1 in 5 women will be sexually assaulted by graduation, or that 5 percent of college women are raped every year.

The difference lies in how the questions are asked. Previous studies have found that many college women who were victims of sexual assault don't believe a crime was committed against them — even if what happened met the legal definition of rape. And the survey doesn't ask specifically about sexual assault committed when victims were too drunk or drugged to consent, the most common type of rape on a college campus.

How the National Crime Victimization Survey differs from other studies

As its name suggests, the National Crime Victimization Survey asks about crime. (Shutterstock)

The National Crime Victimization Survey is, as the name suggests, a survey about crime victimization. That might seem obvious, but it leads to a different method of questioning than other widely publicized surveys on campus sexual assault. And it means whether women see themselves as victims is a key question.

Each year, the survey asks Americans about a wide range of crimes: were you robbed? Were you assaulted? Was your car stolen? One of those crimes is sexual assault, and the survey asks about it in two ways:

(Other than any incidents already mentioned), has anyone attacked or threatened you in any of these ways:… (e) any rape, attempted rape, or other type of sexual attack.

Incidents involving forced or unwanted sexual acts are often difficult to talk about. (Other than any incidents already mentioned), have you been forced or coerced to engage in unwanted sexual activity by (a) someone you didn’t know before, (b) a casual acquaintance? OR (c) someone you know well?

One thing the survey doesn't ask about specifically is incapacitated rape — sex when one person was too drunk or drugged to legally consent. Studies of campus sexual assault have consistently found that this kind of rape is more common than rape under a threat of force. That's one big difference between the National Crime Victimization Survey and other studies about campus sexual assault that have found campus rape to be much more prevalent.

But there's a subtle difference, too: the title of the study itself. "It is … presented to respondents as a survey about criminal victimization," the researchers on the National Crime Victimization Survey wrote. "Because victims of rape or sexual assault may not consider their victimization a crime, this context could discourage or suppress recall and reporting of those incidents."

There's evidence that this does happen. The Centers for Disease Control and Prevention's study on intimate partner violence finds much higher rates of sexual assault in the general population than the crime victimization survey does.

'victims know who did this to them'

The difference lies in how the questions are worded. Researchers in other surveys, including the CDC's, don't necessarily use the term "rape" or "sexual assault" at all. Instead, they ask much more specific questions about what happened, such as "when you were drunk, high, drugged, or passed out and unable to consent, how many people ever had vaginal sex with you?"

Christopher Krebs, the lead researcher on the Campus Sexual Assault Study, a study of two colleges that led to the widely cited "1 in 5" statistic, says the term "rape" carries heavy baggage.

"Women often think of rape as something perpetrated by a stranger, someone they don’t know, someone jumping out from behind a bush or behind a car," he says. "They think of something that happens that’s violent: they had to be hit or kicked or threatened. They think of it as something that happens when you’re around people you don’t know."

And that's not the reality, he says: "Very often, on college campuses, victims know who did this to them."

Some women are reluctant to classify what happened to them as rape

Studies of college women find that a large proportion don't define what happened to them as a crime. In Krebs' survey of women at two large public universities, 56 percent of the victims of forced sexual assault who didn't report their assaults to the police, and 67 percent of victims of incapacitated sexual assault who did not do so, said it was at least partly because it was not "serious enough to report." Slightly more than one-third of women in both categories said it was "unclear if a crime or harm was intended."

This is a common reaction: knowing that something had happened, but being unsure how to define it. "The language we use for a given experience inevitably defines how we feel about it," Susan Dominus writes in the New York Times magazine this week, about a man who had sex with her during her senior year in college, when she was drunk and had refused. "I could not land on language that felt right — to me —about that encounter. I still cannot."

A national survey from the Medical University of South Carolina found that 15 percent of college women who were victims of forcible rape would describe what happened to them as "unpleasant, but not a crime." An additional 32 percent called it a crime, but not rape. For incapacitated rape, the proportions were even higher: 31 percent called it an unpleasant experience, and 40 percent a crime other than rape.

"If you ask women 'have you been raped,' some of them will tell you, 'No, I absolutely have not been raped,'" Krebs said. "But if you start talking to them about experiences they may have had, they tell you about an experience that absolutely would meet the definition of having been raped. And you say 'Do you think you were raped?' and they say 'No, absolutely not.'"