There have been longstanding debates in the scientific community regarding what qualifies as evidence for programs that work with challenging youth. There are also a variety of levels of evidence on a continuum from promising to proven. Aggression Replacement Training[R] has stood the test of time in terms of its scientific underpinning and effectiveness of outcomes. Developed by Arnold Goldstein, Aggression Replacement Training[R] (ART) is a psychoeducational approach to working with young people who experience difficulties with interpersonal relationships and prosocial behavior. ART explicitly teaches an array of prosocial psychological skills to youth who have specific areas of need. Training is delivered in a series of structured learning groups where youth are: (1) Shown examples of expert use of the behaviors that constitute the skills in which they are deficient; (2) Given guided opportunities to practice and rehearse these competent behaviors; (3) Provided with reinforcement, reinstruction, and performance feedback on how well they perform their role-playing enactments; and (4) Encouraged to engage in a series of activities designed to increase the chances that skills learned in the training setting will endure and transfer in home, school, home, community, and other real-world settings. (Contains 2 tables.)