NCJ Number
120553
Date Published
1989
Length
50 pages
Annotation
This article describes methods of polygraph testing, their reliability and validity, technical and practical problems concerning their use, and recent developments for evaluating their outcome.
Abstract
Polygraph techniques are used for two purposes: the detection of deception, the deception test; and the detection of information, the information test. Deception tests are designed to assess credibility by taking responses to simple yes-no questions concerning the crime. In mock-crime experiments conducted in the late 1970s and 1988, the control question polygraph test, a form of deception test, showed 97 percent accuracy on guilty subjects and 93 percent accuracy on innocent subjects. Information tests do not directly assess the credibility of responses but instead measure the relative strengths of physiological reactions to specific questions. In five laboratory experiments conducted from 1959 to 1987, the concealed knowledge test, a form of information test, showed 84 percent accuracy on guilty subjects and 99 percent accuracy on innocent subjects. Poorly socialized persons are thought to be able to deceive the polygraph test because they are adept at lying and deficient in moral development and social conscience, however, most examiners can identify this problem in the pretest interview. 9 tables, 83 references.