Last month a survey of 27 prominent universities revealed that 23 percent of undergraduate women had experienced sexual assault or misconduct while at school. This month holds the halfway point of the “Red Zone,” the weeks between freshman orientation and Thanksgiving break when students are supposedly at the greatest risk of sexual assault. Awareness is high, but the problem of sexual assault on campus has yet to be resolved. Part of the issue is that such offenses remain slippery subjects: difficult to define, to prove and to prevent.

Affirmative consent standards are gaining ground as a tactic to identify and prevent sexual assault at universities. Also referred to as “yes means yes” policies, they define consent as a clear, unambiguous and voluntary agreement to engage in sexual activity.  Real consent is marked by the ongoing presence of a yes rather than the absence of a no — both parties must agree to sexual contact verbally or through clear non-verbal cues, and silence or lack of resistance doesn’t indicate consent. Schools with affirmative consent policies must use this stricter standard to evaluate sexual assault complaints within their campus disciplinary systems.

Though controversial, this approach isn’t new. In 1991, Ohio’s Antioch College became the first in America to mandate ongoing verbal affirmation during sexual encounters. Its “Ask First” policy  was widely ridiculed and even parodied on an episode of Saturday Night Live.  But two decades later, affirmative consent standards have been adopted at colleges across the nation, including every ivy league university except Harvard.

Last September, California became the first state to sign “Yes Means Yes” into law. SB 967 now requires all colleges receiving state funding for student financial aid to adopt an affirmative consent standard to be used when investigating sexual assault complaints and proceeding through the disciplinary process. New York State followed suit with similar legislation this July, and in September, Michigan became the latest state legislature to introduce an affirmative consent law for consideration.

For reasons both moral and practical, schools should be doing everything they can to combat sexual assault. According to a 2011 letter issued by the Department of Education’s Office for Civil Rights, the anti-discrimination law Title IX requires any school that receives federal funding “to take immediate and effective steps to end sexual harassment and sexual violence,” or risk fines and loss of access to funds.

Yet some think that affirmative consent laws go too far, while others believe that they don’t go far enough.

Some legal thinkers worry that the standard is unfair to those accused of sexual assault, pointing out that is nearly impossible to objectively prove that an appropriate level of consent was obtained in a given situation. Other opponents believe that the policies are intrusive and misunderstand the nature of most sexual experiences. And yet others argue that new definitions of consent are too little, too late in a culture that doesn’t take sex seriously enough.

How will changing standards of consent affect student behavior, and the handling of sexual assault cases on college campuses and in the larger criminal justice system? And what does the need for increasingly explicit rules around consent say about our culture’s understanding of sex?

Over the next few days, we’ll hear from: