EFFORTS CHARACTERIZED AS DELINQUENCY PREVENTION HAVE PROCEEDED IN THREE DISTINCT DIRECTIONS AND HAVE BEEN AIMED AT ALL YOUTH, POTENTIAL DELINQUENTS, AND JUVENILE OFFENDERS. CONTEMPORARY APPROACHES TO DELINQUENCY PREVENTION CHARACTERISTICALLY DIRECT THEIR EFFORTS TOWARD INDIVIDUALS AND SMALL GROUPS WITH THESE VARIATIONS: (1) INDIVIDUAL SERVICES; (2) GROUP SERVICES; (3) SPECIAL EDUCATIONAL PROVISIONS; (4) SOCIAL LEARNING; (5) COMMUNITY OUTREACH; (6) ADULT MODELS; AND (7) WORK EXPERIENCE. DESCRIPTIONS OF EACH APPROACH ARE INCLUDED. LARGE-SCALE INTERVENTIONS ARE DERIVED FROM BROAD SOCIAL ANALYSES OF CONDITIONS THAT REQUIRE CHANGE. THEY TAKE THREE FORMS -- AREA INTERVENTION, COORDINATION OF SERVICE, AND RECREATIONAL APPROACHES -- WHICH ARE EXAMINED INDIVIDUALLY IN RELATION TO PROJECTS IN LARGE CITIES SUCH AS NEW YORK (NY), CHICAGO (ILL.), WASHINGTON, D.C., AND MINNEAPOLIS (MINN.). RESULTS ARE PRESENTED FOR THE FIVE SMALL-SCALE AND THREE LARGE-SCALE INTERVENTION TECHNIQUES, AND RESEARCH METHODOLOGY USED IN EVALUATION OF PROGRAMS IS EXAMINED. RESEARCH-ORIENTED DELINQUENCY PROJECTS ARE ALSO REVIEWED IN RELATION TO THE FOCUS ON THE INDIVIDUAL, THE GROUP, THE INSTITUTIONS, OR WORK. THE DISTRIBUTION OF RESULTS FOR ACTION-ORIENTED PROJECTS AS COMPARED TO SPECIAL RESEARCH PROJECTS DIFFER ACCORDING TO IMPACT, EVALUATION, AND SELECTION OF COMPARISON GROUPS. A GENUINE MOVEMENT SEEMS TO BE UNDERWAY IN THE FIELD OF COMMUNITY-BASED REFORM; IT IS DISCUSSED ALONG WITH THREE INCREASINGLY IMPORTANT FACTORS IN INTERVENTION -DIVERSION, ABSORPTION, AND NORMALIZATION. YOUTH SERVICE BUREAUS ARE ASSESSED AS PREVENTERS, AND THREE PREVENTION MODELS ARE DESCRIBED. POLICY DIRECTIONS ARE PROPOSED IN SEVEN AREAS: LEGAL, DIVERSION, DEINSTITUTIONALIZATION, RESTRUCTURING THE JUVENILE COURT, SCHOOL/WORK CONNECTIONS, EDUCATIONAL RESPONSIVENESS, AND KNOWLEDGE BUILDING. AN APPENDIX CONTAINS A PAPER ON A FAMILY-ORIENTED NATURAL SYSTEMS PREVENTION MODEL. BIBLIOGRAPHICAL REFERENCES ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED--DAG)