David E. Nagle


The polygraph is an instrument which measures and records certain physiological data of a subject under controlled conditions in an attempt to detect deception. It operates on the theory that an individual exhibits certain predictable physiological characteristics every time that he intentionally tells a lie. While some critics question the reliability and validity of polygraph test results, the use of the polygraph in the workplace reveals that it has gained acceptance by a sizable segment of American business as an effective tool in personnel matters.