The effectiveness of many specific drug prevention strategies is not known yet, primarily because of poor program evaluation design. However, evidence has shown that interventions based on the social influence model are effective. Regardless of strategies employed, all prevention programs must start early; involve coordinated efforts with the community; include students, parents, teachers and community members in the planning process; and implement a systematic and comprehensive program. The program should be based on a clear hypothesis; contain different strategies for different populations; and give special attention to the needs of at-risk students. (ABL)