NCJ Number
113599
Date Published
1988
Length
65 pages
Annotation
This project used 241 confirmed and unconfirmed polygraph charts from examinations conducted by the U.S. Secret Service during FY 1983 and FY 1984 to determine the validity of the control question technique for assessing truth and deception in criminal investigations.
Abstract
The study also assessed: (1) the performance of polygraph examiners with different educational backgrounds and experience with polygraph techniques; (2) the efficacy of a computer method for interpreting the outcomes of polygraph examinations; and (3) the extent to which laboratory mock-crime experiments provide information and results that have implications for field applications. The project used 6 polygraph examiners and a psychophysiologist at the University of Utah to 'blindly' interpret the 241 cases selected by computer program from 1,757 polygraph examinations conducted by the U.S. Secret Service at its Washington, D.C., headquarters. The sample also was subjected to computer interpretation using algorithms. Results indicate that the accuracy of human and computer interpretations was very high, ranging from 91 percent to 96 percent correct on confirmed truthful answers, and 85 percent to 95 percent correct on confirmed deceptive answers. Blind interpretation produced somewhat lower accuracies, ranging from 63 percent to 85 percent on truthful answers, and 84 percent to 95 percent correct on deceptive answers. Accuracy of the computer interpretation ranged from 95 percent to 96 percent on confirmed truthful suspects, and 83 percent to 96 percent on confirmed deceptive subjects. 38 references.