Most prevention intervention research is school-based and designed to deter completely or to delay the onset of drug use. Drug abuse prevention efforts have been strongly influenced by programs aimed at reducing cardiovascular risk. The nicotine model, like drug abuse prevention research, is biologically based. The principal focus of the remainder of the chapter is on school-based interventions; special emphasis is given to preliminary analyses from a community-wide evaluation of Project DARE (Drug Abuse Resistance Education), a primary prevention program taught in 17 segments to sixth- graders; the instructor is a police officer. Outcomes, process, and impact are the three most important considerations when assessing the success of a given intervention. Most school-based programs are evaluated using the individual student as the unit of analysis; students in experimental schools are compared with those in control schools on salient outcome factors. The Project DARE program implemented by the Lexington-Fayetee County Kentucky Police Department is discussed in detail. Implementation and design, measurement, and analysis issues are considered. 5 tables and 36 references