THE POLICE TASK PERFORMANCE INDEX (PTPI) WAS DEVELOPED IN CONJUNCTION WITH A LARGE, METROPOLITAN COUNTY POLICE DEPARTMENT TO GIVE ADMINISTRATORS A TOOL FOR MEASURING PATROL PERFORMANCE. IT IS A QUANTITATIVE INDICATOR WHICH COMPARES WEIGHTED SCORES FOR TASKS REQUIRED WITH WEIGHTED SCORES FOR TASKS PERFORMED. THE PROCESS OF DEVELOPING THE PTPI IS DESCRIBED STEP-BY-STEP. AN EXPERT PANEL AND THE DELPHI TECHNIQUE (WHICH USES QUESTIONNAIRES TO OBTAIN INFORMATION FROM A GROUP) VALIDATED THE FINAL INDEX. MATHEMATICAL FORMULAE USED TO DEVELOP WEIGHTS FOR EACH ITEM, DATA USED TO DEVELOP THE INDEX, AND THE FINAL WEIGHTED INDEX ARE ALL PRESENTED. USE OF THE PTPI IS DEMONSTRATED BY DEVELOPING A SPECIFIC INDEX FOR THOSE POLICE TASKS PERFORMED BY A UNIFORMED PATROLMAN AT THE SCENE OF A MEDICAL EMERGENCY, AND USING IT TO EVALUATE PATROL PERFORMANCE DURING TWO SAMPLE CASES--A SHOPPING CENTER TWO-CAR COLLISION AND A SHOOTING IN A PRIVATE RESIDENCE. THE INDEX IDENTIFIES THOSE FACTORS WHICH INTERFERE WITH THE OFFICER'S PERFORMANCE OF FIRST AID AND CAN HELP ESTABLISH PRIORITIES. REFERENCES ARE INCLUDED. (GLR)