Effects of Information and Practice on Detection of Deception

• NCJ Number: 82947
• Author(s): L I Rovner; D C Raskin; J C Kircher
• Date Published: 1978
• Length: 5 pages
• Sale Source: National Institute of Justice/
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America
• Note: Presented at the Society for Psychophysiological Research, Madison, Wisconsin, September 17, 1978.

Annotation

This paper describes a research project involving the physiological detection of deception (PDD) technique and the effectiveness of the control-question (CQ) technique in polygraph examinations.

Abstract

Seventy-two male subjects were recruited from the local community to participate in the study. Thirty-six guilty subjects received taped instructions to steal a ring from a secretary's office, and 36 innocent subjects were simply informed that a theft had been committed. All subjects were instructed to deny having committed the theft when they were administered a CQ polygraph test. Prior to that test, 24 subjects in the control group (12 innocent and 12 guilty) simply waited in a room for 40 minutes. Twenty-four subjects in the information group received detailed information about the polygraph, the CQ test, pertinent physiological responses, and suggestions about methods to appear innocent on the test. The remaining 24 subjects (in the information plus practice group) received the same information and were given two practice polygraph examinations and feedback regarding performance. Following the treatment session, each subject was given a CQ polygraph examination by an examiner who did not know the subject's guilt, innocence, or treatment group. Test scoring was based upon measures of skin conductance, changes in blood pressure, respiration, and digital vasomotor activity. Evaluation for the control group and the information only group was identical: 88 percent correct, 4 percent wrong, and 8 percent inconclusive. For the information plus practice group, 62.5 percent of the evaluations were correct, 25 percent were wrong, and 12.5 percent were inconclusive. The study results indicate a high degree of effectiveness of the CQ technique with naive subjects and with subjects who are provided with information only. The effectiveness of the CQ technique is weakened by the combination of information, practice, and feedback. The paper includes three references.