IN THE PERIOD FROM 1964 TO 1978, CRIME HAS CONTINUED TO RISE, POLICE MANPOWER IN ENGLAND AND WALES HAS INCREASED BY ONE-THIRD, AND CIVILIAN STAFF HAVE MORE THAN DOUBLED. THERE HAS BEEN A STEADY STREAM OF RESEARCH, PRIMARILY FROM THE UNITED STATES, THAT HAS BEGUN TO CALL INTO QUESTION MUCH THAT IS CENTRAL TO THE DETERRENT ROLE OF POLICE. IN GREAT BRITAIN, EVALUATIVE RESEARCH HAS BEEN UNDERTAKEN MAINLY WITHIN THE CONTEXT OF PENAL TREATMENT AND FOCUSES ON POLICE EFFECTIVENESS. POLICE OFFICERS ARE EFFECTIVE TO THE EXTENT THEY ACHIEVE THEIR OBJECTIVES, AND POLICING IS PRODUCTIVE TO THE EXTENT IT ACHIEVES ITS OBJECTIVES COST-EFFECTIVELY. ASSESSING POLICE EFFECTIVENESS IS, THEREFORE, A PROCESS THAT OCCURS PRIOR TO ASSESSING PRODUCTIVITY. RESEARCH STUDIES ARE CITED THAT ADDRESS PUBLIC CALLS FOR ASSISTANCE AND THE DEPLOYMENT OF POLICE RESOURCES, THE EFFECTIVENESS OF POLICE TRUANCY PATROLS IN REDUCING CRIME, THE EFFECT OF PUBLICITY CAMPAIGNS ON VEHICLE SECURITY, AND TARGET HARDENING. METHODOLOGICAL PROBLEMS IN STUDYING POLICE EFFECTIVENESS CONCERN EXPERIMENTAL DESIGNS, CRITERIA OF EFFECTIVENESS, AND DISPLACEMENT (I.E., INSTEAD OF CRIME BEING PREVENTED, IT MAY BE THAT OFFENDERS ARE MERELY SHIFTING THEIR ACTIVITIES TO LOCALITIES WHERE POLICE OFFICERS HAVE NOT INTENSIFIED THEIR EFFORTS OR TO TARGETS THAT HAVE NOT BEEN GIVEN SPECIAL PROTECTION). RESEARCH IS PLANNED TO ASCERTAIN THE EFFECTIVENESS OF CENTRAL DETERRENT ACTIVITIES OF THE POLICE, INCLUDING CONVENTIONAL PATROL, SURVEILLANCE, AND CRIMINAL INVESTIGATION. THE CONSEQUENCES OF IMPROVEMENTS IN SECURITY WILL CONTINUE TO BE STUDIED. ADDITIONAL INFORMATION RELEVANT TO RESEARCH ON POLICE EFFECTIVENESS IS CONTAINED IN APPENDIXES. REFERENCES ARE INCLUDED. (DEP)