THERE ARE FOUR BASIC APPROACHES THAT CRIME PREVENTION PROGRAMS MAY TAKE: (1) PAID PUBLIC POLICING ACTIVITIES, (2) ENVIRONMENTAL DESIGN, (3) PRIVATE-MINDED ACTIONS, AND (4) PUBLIC-MINDED ACTIONS. OBSTACLES WHICH MAKE EVALUATION OF CITIZEN CRIME PREVENTION PROGRAMS DIFFICULT INCLUDE THE FOLLOWING: THE IDENTIFICATION OF MEASURABLE OBJECTIVES, THE IDENTIFICATION OF A TARGET POPULATION, THE ABILITY TO CONTROL THE PROGRAM, THE ABILITY TO MEASURE KEY FEATURES OF THE INTERVENTION PROCESS, AND THE AVAILABILITY OF SUFFICIENT TIME SO THAT THE SHORT AND LONG-TERM EFFECTS OF THE INTERVENTION CAN BE ASSESSED. CITIZEN PATROL GROUPS CAN BE TYPED AND INCLUDE BUILDING PATROLS, IN WHICH VOLUNTEERS OR PAID GUARDS MAINTAIN SURVEILLANCE OVER BUILDINGS AND NEIGHBORHOOD PATROLS, IN WHICH VOLUNTEERS OR PAID GUARDS MAINTAIN SURVEILLANCE OVER A SMALL GEOGRAPHIC AREA. NEIGHBORHOOD PATROLS' EFFECTIVENESS CANNOT BE DETERMINED BY TRADITIONAL RESEARCH METHODS BECAUSE THE AREA COVERED BY A NEIGHBORHOOD PATROL IS OFTEN POORLY DEFINED, AND THE EFFECTS OF THE PATROL CANNOT BE SUFFICIENTLY DISTINGUISHED FROM EFFECTS RELATING TO POLICE AND OTHER CRIME CONTROL ACTIVITIES. FINALLY, THE QUALITY AND QUANTITY OF LOCAL POLICE ACTIVITIES COULD CHANGE AS A RESULT OF THE PRESENCE OF A NEIGHBORHOOD PATROL. IN CONTRAST, THE EFFECTIVENESS OF BUILDING PATROL PROGRAMS CAN BE ASSESSED. COMPETITION WITH THE POLICE AND OTHER AGENCIES WOULD NOT BE A FACTOR IN THIS KIND OF AN EVALUATION, AND THE SAMPLE IS USUALLY CLEARLY DEFINED. THE IMPLICATION OF THIS RESEARCH IS THAT NEGATIVE FINDINGS OF CRIME PREVENTION PROGRAMS ARE NOT NECESSARILY VALID. IN EXAMINING THE FINDINGS OF AN EVALUATION, IT IS IMPORTANT TO CONSIDER THE LIMITATIONS OF THE EVALUATION, ITSELF. LIST OF REFERENCES IS PROVIDED.