The finding that one in five women are sexually assaulted in college is as widely known as it is startling. Countless media reports repeat and recycle the alarming statistic, and it headlined the initial report introduced by Vice President Biden from the White House Task Force to Protect Students from Campus Assault.

But how trustworthy is that figure of one in five? An earlier poll found it was more like 1 in 40, but should it matter whether the real number is closer to the high or low end of the scale?

“We know there are rapists on campus that target vulnerable women,” says Christina Hoff Sommers, a resident scholar at the conservative American Enterprise Institute, who thinks getting the numbers right is important. “Inflated figures lead to ineffective policies and breed panic and over-reach.”

Sommers makes a good case that the one-in-five finding is inflated, and that the administration and the media have been careless in disseminating it as fact. It comes from a 2007 study conducted by the Justice Department’s National Institute of Justice, a web-based survey of two large public universities, one in the Midwest, and one in the South. Female undergraduates aged 18 to 25 took part in the anonymous random sample, and each received a $10 certificate to Amazon for participating.

Web surveys are automatically suspect, and the response rate was less than half, 42 percent, “which is miserable,” says Sommers. The researchers themselves cautioned against over-generalizing from the 5,446 respondents to the entire country’s college population, and Sommers cites the danger of selection bias, where people who feel most strongly respond.

“I always like to know what did they ask,” she says, reserving her strongest criticism for the expansive definition of sexual assault that is now part of the lexicon, particularly factoring in the role of alcohol. She notes that in some 70 percent of assaults categorized in the poll, alcohol was involved, and the woman was incapacitated.

“If sexual intimacy under the influence is by definition assault, sexual relations down through the ages would be classified as an assault,” says Sommers, a former professor of philosophy who has made a name for herself as an outspoken critic of contemporary feminism. “What might be dismissed as a foolish drunken hookup is now a felony rape.”

Since the White House report, titled “Not Alone,” was released in late April, lawmakers have looked for ways to curb what appears to be the soaring number of sexual assaults on college campuses. Democratic Sen. Claire McCaskill, a former prosecutor of sex crimes, will introduce bipartisan legislation in the next few weeks that Sommers and other critics worry will further confuse and blur the lines around what might once have been dismissed as a sexual misunderstanding, with the burden of proof shifting significantly from the woman to the accused.

The details of what McCaskill will propose are not yet fully known, but the expectation is that the legislation will call for consent every step of the way in a sexual encounter. The consent doesn’t have to be verbal. It can be implicit and it can be body language, but it must be clear and unambiguous.

Stuart Taylor Jr., a lawyer and a journalist, joined Sommers on a recent panel at the conservative Independent Women’s Forum to decry what he called “the pressure to treat all drunken sex as rape.” He said that Department of Education rules have changed during the Obama administration from convincing evidence to preponderance of evidence in assessing guilt.

“Preponderance means 51 percent sure and 49 percent not, you find him guilty,” he said, calling it “a degrading of due process for males who may have been wrongly accused.”

Taylor said he could imagine young men today tape-recording permission at every stage. “Do I exaggerate?” he asked, conceding “perhaps,” then adding when it’s his word against hers, unless it’s on tape, there’s an incentive to document your case against what he called “de facto extreme feminist presumption of guilt.”

Taylor’s prediction of what lies ahead is supported by a comment made to The Washington Post by George Washington University Law School professor John F. Banzhaf III, who said he is seeing more cases of young men using video of sexual encounters to defend themselves against assault or rape.

A recent column by conservative columnist George Will said progressive policies expanding the definition of rape “make victimhood a coveted status that confers privileges,” and when that happens, “victims proliferate.” Will’s observations seemed to trivialize the very real problem of rape and assault on college campuses, and he ran into a buzz saw of criticism from women’s groups that resulted in at least one newspaper canceling his column. Asked about Will’s column, Taylor said its flaw was in the tone, which implied that campus assault was not a big problem, but rather a privilege to be a victim. Taylor said that being perceived as a victim was the distinction that Will failed to make.

Unlike most legislation in Congress, the effort to clarify and modernize the federal guidelines around how to handle sexual assault on campuses is a bipartisan effort, perhaps because members of both parties have daughters. Sommers has legitimate questions about the slippery slope of government getting involved, but any argument that appears to minimize the problem will get slapped down by those who know better, and rightly so.