s "an instrument used to measure the autonomic nervous system responses in terms of blood pressure, pulse rate, respiration rate and galvanic skin response." In theory when a person tells a lie, fear of detection causes uncontrollable reactions in these physiological areas, which the polygraph indicated with inked lines on a moving paper scroll. Polygraph examinations have been approved as a way to determine guilt of criminal suspects, to exonerate innocent suspects, to protect national security, and to maintain employee honesty. Polygraph examinations have, at the same time, been criticized for providing inaccurate and misleading information, for failing to detect security risks, for interfering with the rights of private citizens, and for lowering employees' morale. At the center of controversy over the use of polygraph examinations is the question of its validity: does a polygraph examination actually identify truthful and non-truthful individuals?
             The most obvious concern is tat lie detectors do not actually tell you whether the subject has lied but rather deed on physiological responses recorded during the questioning of a person. An example of where polygraphs can give erroneous "results" is when nervous persons are tests. Person of a nervous disposition may display galvanic responses, which may be interpreted as indicating that the person Is lying when they are answering questions truthfully but are feeling stressed. Others are able to "beat the lie detector". One method may be for a person to state a proposition numerous times until the person accepts its validity and consequently passes a lie detector test (e.g. "the earth is square, the earth is square...").
             When courts have been called on to resolve disputes concerned with use of polygraph examinations, they have had to consider both the technique's validity and whether its use, however valid, interfaces with other values that the law seeks to protect. Indeed, for ...