The monograph first provides a working definition of 'community-based alternatives' to ensure a common understanding of terminology among the readership. An historical perspective on the development of this concept then traces how community programs have evolved from isolated reforms to concerted efforts for improving the services of the entire juvenile justice system. Contemporary theories on the causes for juvenile delinquency are then presented with corollary hypotheses on the most effective means for reducing juveniles' antisocial behavior. The major theories explaining delinquency indicate that commitment and bonding to conventional and adult-approved activities, particularly school work and employment, differentiate delinquent from nondelinquent juveniles. This suggests community-based alternatives that foster associations with conventional peers and adults; encourage and enable participation in school, jobs, and other community activities; reinforce positive socialization processes that build a stake in conformity; discourage coercion or retaliation; and provide opportunities for activities that lead to normative adult roles. The monograph classifies alternatives to the juvenile justice system in general categories for evaluation research. It then translates the historical perspective, theoretical underpinnings, and evaluation findings from the previous discussion into a set of general policy guidelines for considering and approving technical assistance activities in this goal area. 116-item bibliography.