THE POLYGRAPH RECORDS PHYSIOLOGICAL REACTIONS PRODUCED WHEN A HUMAN BODY ATTEMPTS TO PROTECT ITSELF FROM DANGER BY TELLING A LIE. THE SUCCESS OF A POLYGRAPH DEPENDS UPON THE FORMULATION OF BOTH THE TEST QUESTIONS PERTAINING TO THE CRIME AND ON THE CONTROL QUESTIONS USED. THE TEST SHOULD BE USED TO ACCOMPANY A CRIMINAL INVESTIGATION IN BORDERLINE CASES, TO HELP VERIFY REPORTS OF VICTIMS, AND TO DISCLOSE EXAGGERATIONS BY EYEWITNESSES. PREVALENT MISCONCEPTIONS ABOUT THE POLYGRAPH ARE LISTED. THEY INCLUDE THE IDEA THAT THE POLYGRAPH EXAMINATION PROVIDES A SIMPLE SHORTCUT TO THE COMPLETION OF AN INVESTIGATION, THAT THE EXAMINATION IS PAINFUL, AND THAT THE EXAMINATION IS INFALLIBLE. THE ATTITUDE AND THE ROLE OF THE INVESTIGATOR IS A SIGNIFICANT FACTOR IN THE EXAMINATION. BEFORE USING THE POLYGRAPH, THE INVESTIGATOR SHOULD NARROW THE SUSPECT FIELD DOWN TO THE MINIMUM NUMBER OF PERSONS. THE PRIME SUSPECT SHOULD BE THE FIRST TESTED. THE INVESTIGATOR MUST BE CAREFUL NOT TO DISCUSS THE FACTS OF THE CASE WITH SUSPECTS, BUT MUST PREPARE A DETAILED AND ACCURATE ACCOUNT OF THE FACTS FOR THE EXAMINER. MEASURES FOR REASSURING THE SUSPECT AND INSURING THAT THE SUSPECT IS AT HIS PHYSICAL NORM AT THE TIME OF THE EXAMINATION ARE DISCUSSED. POSSIBLE FACTORS THAT MIGHT CAUSE AN INCONCLUSIVE POLYGRAPH EXAMINATION ARE TENSION BETWEEN THE EXAMINER AND THE SUSPECT OR INADEQUATE CHART RESPONSES. INVESTIGATORS SHOULD USE ONLY QUALIFIED POLYGRAPH EXAMINERS IN THEIR INVESTIGATIONS. (DAG)