ABSTRACT
The type of polygraph examination most commonly used in criminal investigations in the US is the control question test. Although many experts agree that numerically scored control question tests are about ninety percent accurate when criminal suspects are examined under appropriate conditions, there exists no method by which the field examiner can estimate the accuracy of individual control question tests. The federal scoring system for evaluating single issue control question tests in the field requires a final test score of +6 or higher for a decision of truthfulness and -6 or lower for a decision of deception. The data consisted of the numerical scores obtained from the first three charts of the federal zone comparison control question test, in which three physiological measures were scored: respiration, skin resistance and cardiovascular activity as measured by a pressurized arm cuff. There are several approaches that can be taken when estimating the probability of errors associated with individual control question tests.
