One in five women who attended college during the past four years say they were sexually assaulted, according to a Washington Post-Kaiser Family Foundation poll published this summer, but only 11 percent told police or college authorities.

The reasons for the underreporting vary, but there seem to be four main pitfalls: Victims don’t want to draw attention to themselves or their assailants, don’t know if the incident truly constituted “rape,” are worried they won’t be believed, or don’t know whom to report to.

A new site, Callisto, aims to make it easier for college students to document—and report, if they wish—their sexual assaults. With Callisto, a student can fill out a timestamped record of the incident and then choose between three different next steps.

First, they can send it directly to their campus Title IX coordinator, the point-person for student investigations. The writing process helps, Callisto’s creators believe, because it might reduce the odds that college administrators will handle the matter insensitively.

“Our hope is that ... the Title IX coordinator will be able to have a more nuanced conversation,” said Tracey Vitchers, director of development and operations for Sexual Health Innovations, the nonprofit that designed Callisto. “That way the survivor won't be in a position where they have to tell and tell and retell what happened to them.”

Second, the student could simply save it and decide whether to file it later. Finally, the student can put the report into “matching,” meaning the report will only be filed if someone else reports an assault by the same perpetrator.

It’s this last option that makes Callisto unique. Most rapes are committed by repeat offenders, yet most victims know their attackers. Some victims are reluctant to report assaults because they aren’t sure whether a crime occurred, or they write it off as a one-time incident. Knowing about other victims might be the final straw that puts an end to their hesitation—or their benefit of the doubt. Callisto’s creators claim that if they could stop perpetrators after their second victim, 60 percent of campus rapes could be prevented.

This kind of system is based partly on a Michigan Law Review article about “information escrows,” or systems that allow for the transmitting of sensitive information in ways that reduce “first-mover disadvantage.” According to the article, economists also refer to this as the “hungry-penguin problem:”

Hungry penguins gather at the edge of an ice floe, reluctant to dive into the water. There is food in the water, but a killer whale might be lurking, so no penguin wants to dive first.

With Callisto, no one has to be the first penguin. And as game theorist Michael Chwe points out, the fact that each person creates her report independently makes it less likely they’ll later be accused of submitting copycat reports, if there are similarities between the incidents.

Callisto is being piloted at Pomona College and the University of San Francisco this year, with plans to expand it further if it’s successful.