Yes, there are two criteria in law. The offender will not, by reoffending, present an undue risk to society before the expiration of their sentence, and—it's not an “or”, it's an “and”—the release of the offender will contribute to the protection of society by facilitating his or her reintegration as a law-abiding citizen.
Those are the two criteria that the board is most interested in and, by law, must consider before making a decision.