Nearly one in five women who attend college will become the victim of rape or attempted rape before graduation, a Justice Department-funded study found. But too many schools aren't reporting the scope of the problem accurately.

A nine-month investigation by the Washington-based Center for Public Integrity has found that many colleges and universities are still downplaying their crime statistics, despite a 19-year-old federal law requiring full disclosure.

The Clery Act is named for Jeanne Clery, who was murdered by a fellow student in her dorm room at Lehigh University in 1986. The law requires schools to report crimes occurring on or near their campuses annually, in specific categories of offenses.

But in 2006, 77 percent of four-year colleges nationwide reported no sexual offenses. Locally last year, Villanova University and St. Joseph's University reported zero sexual offenses. Temple University reported two, out of an enrollment of more than 35,000.

Pennsylvania State University's main campus, with 44,000 students, reported nine sex offenses. In contrast, Ohio State reported 32 forcible sex crimes out of an enrollment of 53,000. (A loophole in the federal law is that it fails to include crimes committed at most off-campus housing.)

In 2007, the U.S. Education Department fined La Salle University $110,000 for ignoring crime data, including 28 sexual assaults. The school appealed and then settled for $87,500, with no admission of fault.

Often, young women who have been assaulted at college remain silent out of fear or embarrassment. But the CPI report found that victims of sexual assault face institutional barriers when they do seek justice on campus. Some of them, after enduring inconclusive disciplinary proceedings, are even told by school officials that they cannot talk about the incident.

The CPI's investigators interviewed 33 women who reported being raped by other students. The experience of Mallory Shear-Heyman, who was a sophomore at Bucknell University in 2003, is typical of what they found.

Shear-Heyman reported being raped in her dorm by another student. She agreed to take part with her alleged attacker in an off-the-record university proceeding called "voluntary facilitated dialogue," in which a male and female administrator guide the discussion. A waiver specified that any information first disclosed in mediation could not be used in other school proceedings.

The male student apologized and implicated himself. The waiver didn't prevent Shear-Heyman from pursuing criminal charges. But she said when she considered it, the deans professed to not remembering the alleged admissions.

No action was taken against the male student, and, years later, Shear-Heyman regrets having participated in the confidential hearing. (Bucknell officials said that they followed school policy explicitly in this case, and that they always inform students that mediation does not preclude them from pursuing criminal charges.)

Kristen Lombardi, an author of the CPI report, said a rape victim should report the incident to law enforcement and get tested at a hospital or medical center to preserve possible evidence. Neither of those steps prevents a student from later deciding against pursuing criminal charges in favor of a confidential campus proceeding.

Many schools have improved the accuracy of their crime reporting in recent years, but not enough. Too many colleges take advantage of loopholes in the federal law - for example, not tallying any suspected sexual assault that is reported to certified counselors, who enjoy a privacy exemption.

Colleges and universities still aren't providing completely accurate data about sex offenses against students. They owe their community a greater level of disclosure, and stronger advocacy for student victims.