Critics of the "affirmative consent" movement sweeping U.S. colleges, including in Hawaii, claim that what amounts to a redefinition of consensual sex could turn the romantic trysts of even willing, loving couples into grounds for a rape accusation.

That fear is overblown, but the naysayers do rightly highlight the need for precise language in the emerging standards, which are intended to improve how amorous college students communicate and, more directly, how colleges evaluate sexual-assault complaints within the campus disciplinary system.

The effort is expected to have a notable impact on university investigations of cases commonly described as "date rape," where the parties know one another.

The "yes means yes" campaigns, evident here in a new University of Hawaii policy and in bills pending in the Legislature, compel a more accuser-centered approach in campus investigations.

The "affirmative consent" standard requires there be unambiguous, conscious, mutual agreement by each participant to have sex.

In the "no means no" days, the burden often unfairly fell on the victim — usually a female — to prove that she tried to fight the guy off.

The new UH policy and the pending legislative measures, companions House Bill 451 and Senate Bill 387, are laudable attempts to improve the safety of students, and, more broadly, to help young adults develop the healthy sexual attitudes and open, respectful communication necessary to navigate sometimes confusing social terrain. But they fall short of the clarity necessary to thwart sexual predators, who exist on college campuses just as they do in the general population, and others who commit sexual misconduct, without exposing innocent people to baseless allegations.

Most problematic is the vague definition of what constitutes "affirmative consent." The bills never define it — they only say what it isn’t. Language stating that a person who is sleeping or incapacitated by alcohol, drugs or medication cannot give consent; and that silence, lack of protest or lack of resistance do not equal consent is fine as far as it goes. But failing to define affirmation flaws these measures.

The new UH policy does a better job, defining sexual consent as "affirmative words or actions that show a knowing and voluntary agreement to engage in mutually agreed sexual activity (including pictures/ video)." But verbiage later in the policy injects ambiguity, with a long list of sometimes vague descriptions of instances when mere assent (affirmative statement or action) does not constitute consent after all.

Both the UH policy, in effect as of this week, and the pending bills, if approved, apply only to UH administrative investigations, which could result in punishment such as a student’s expulsion.

Criminal cases, in which the victim calls the police, are handled by law enforcement and will continue to be.

Campus sexual assault is a serious issue that needs urgent and sustained attention. The University of Hawaii-Manoa Department of Public Safety received reports of 11 forcible sex assaults on campus in 2012 — the most recent year for which data is available — nine of which occurred in dorms or other residential facilities.

Efforts to combat this scourge must also address common associated factors — drunkenness is a major one — and encourage all rape victims to call the police.

Rigorous criminal prosecutions are a path to justice, regardless of the negative effects on a university’s reputation. Discouraging binge drinking and urging bystanders to intervene when potential victims are vulnerable are important, too.

Promoting open, active communication among sexually active students, as the "yes means yes" campaigns do, is sure to help, but it is too soon to codify this "affirmative consent" standard into state law.

UH should refine its new policy to improve it, without legislative intervention.