These evaluations have focused on the three main types of interventions: couple or couple group treatment; group treatment of batterers; and the response of the criminal justice system, particularly the police. Evaluations of couple treatment suffer from serious methodological and definitional problems, and those focusing on group treatment of batterers have reported nonviolence levels of 59 to 75 percent after treatment. Studies of criminal justice interventions have not made clear whether prosecution helps end violence, but indicate that arrest and men's group treatment may be the most promising option. Success has been variously defined in terms of the level of violence and the nature of the abuse. Recommendations for further research and methodological improvements.