Since 1974, the U.S. federal government has funded four major multiyear evaluation studies to determine the relative effectiveness of different approaches to the treatment of child abuse and neglect. A total of 89 different demonstration treatment programs were studied, and data on 3,253 families experiencing difficulties with abuse and neglect were gathered. Collectively, the studies document treatment approaches which improve clients' functioning (notably lay counseling and various group services including Parents Anonymous, group therapy, and parent evaluation) and suggest greater success with clients experiencing difficulty with sexual abuse than other forms of maltreatment. However, overall the studies show that one-third or more of the parents served by these intensive demonstration efforts maltreated their children while in treatment, and over one-half of the families served continued to be judged likely to mistreat their children following termination.