SPECIAL METHODOLOGICAL PROBLEMS ARE POSED IN THE EVALUATION OF PREVENTIVE POLICING. THE MEASUREMENT OF SUCCESS OF ANY SUCH CRIME PREVENTION SCHEMES CANNOT RELY ON THE SAME EMPIRICAL MEASURES USED IN THE EVALUATION OF REACTIVE POLICING; EVALUATION OF PROACTIVE POLICING MUST SHOW THAT THE CHANGES HAVE RESULTED FROM POLICY SHIFT OR INNOVATIONS. ALSO, POLICE EFFORTS MIXED WITH THE EFFORTS OF OTHER TYPES OF ACTORS IN BROAD-BASED EFFORTS TO CHANGE A COMMUNITY MILIEU MAKE IT DIFFICULT TO ISOLATE AND EVALUATE THE PARTICULAR CONTRIBUTION OF THE POLICE IN TERMS OF FINAL OUTCOMES. EVALUATIONS MUST ALSO CONSIDER THE IMPACT OF INNOVATIONS ON POLICE OFFICERS THEMSELVES, AS WELL AS THE POLICE ORGANIZATION. GIVEN THESE METHODOLOGICAL CHALLENGES TO EVALUATION, THE FOLLOWING STEPS SHOULD BE UNDERTAKEN IN EVALUATING PROACTIVE POLICING EFFORTS: (1) IDENTIFY THE ACTIVITIES DERIVED FROM THE PROACTIVE POLICY AND THE MAJOR OBJECTIVES SOUGHT THROUGH EACH ACTIVITY, (2) MAKE ALL ELEMENTS OF OBJECTIVES CONCRETE WITH A VIEW TOWARD MEASUREMENT AND DATA COLLECTION, (3) DETERMINE THE TYPE OF INFORMATION NEEDED TO MEASURE THE ACHIEVEMENT OF EACH STAGE OF AN OPERATION, (4) DETERMINE THE INFORMANTS NECESSARY TO SUPPLY THE INFORMATION, AND (5) DETERMINE THE QUESTIONS NECESSARY TO OBTAIN THE REQUIRED INFORMATION. EVALUATION OF THE KINDS OF ENTERPRISES ENVISIONED BY PROACTIVE POLICING MUST NECESSARILY BE LIMITED BY THE CONCEPTUALIZING OF OBJECTIVES IN TERMS THAT ARE MEASUREABLE. INITIAL STUDIES, WHICH SHOULD BE SMALL-SCALE INVESTIGATORY PROJECTS DESIGNED TO GENERATE HYPOTHESES, WILL ONLY BE CAPABLE OF PRODUCING TENTATIVE CONCLUSIONS. NO REFERENCES ARE INCLUDED. (RCB)