THE POLICE FIELD SERVICE FOCUS OF THE EVALUATION RESEARCH REVIEW IS BASED ON POLICE PATROL AND INVESTIGATION FUNCTIONS. STEPS IN THE STRUCTURAL ANALYSIS OF THESE FUNCTIONS ARE DESCRIBED AND ILLUSTRATED: SELECTION OF HYPOTHESES; SELECTION OF PERFORMANCE CRITERIA BY WHICH TO TEST HYPOTHESES; DESIGN OF AN EXPERIMENTAL MECHANISM FOR TESTING; EXECUTION OF THE EXPERIMENTAL MECHANISM; AND EVALUATION OF EXPERIMENTAL RESULTS. COMMON FIELD SERVICE PERFORMANCE MEASURES ARE NOTED FOR CRIME PREVENTION, POLICE RESPONSE TIME, AND PATROL PRODUCTIVITY-MANPOWER ALLOCATION STUDIES. THE EVALUATION OF EXPERIMENTAL RESULTS IS DISCUSSED. MAJOR PATROL AND INVESTIGATIVE STUDIES ARE REVIEWED, INCLUDING THE KANSAS CITY PATROL EXPERIMENT (MISSOURI), THE KANSAS CITY RESPONSE TIME ANALYSIS (MISSOURI), THE ST. LOUIS AVM EXPERIMENT, (AUTOMATIC VEHICLE MONITORING), THE WORCESTER CRIME IMPACT PROGRAM (MASSACHUSETTS), THE WILMINGTON SPLIT-FORCE EXPERIMENT (DELAWARE), AND SAN DIEGO'S ONE-OR-TWO-OFFICER UNITS. THE USE OF SCIENTIFIC TECHNIQUES TO FACILITATE CRIME RESOLUTION AND THE CRIMINAL INVESTIGATION PROCESS ARE DESCRIBED. SAMPLE RESEARCH HYPOTHESES ARE NOTED. NOTES ARE INCLUDED. (DEP)