Throughout the past decade I have been involved in various preventionoriented programs. These projects have ranged from research and evaluation on crime prevention, to projects dealing with preventing illness, to ones dealing with home fire prevention. I have maintained a strong belief in the efficacy of a prevention approach to dealing with social problems, as opposed to more traditional treatment approaches. However, we do not really have good evidence that such prevention programs are effective (Kelly, Snowden, & Munoz, 1977; Heller, Price, & Sher, 1980). We need to create bodies of knowledge that help us understand the workings of and the theories behind prevention programs. But there are many barriers to doing so. This paper is about those barriers, and about ways we might cope with them.