NCJ Number
225357
Journal
Polygraph Volume: 37 Issue: 2 Dated: 2008 Pages: 149-164
Date Published
2008
Length
16 pages
Annotation
This study tested modifications to the psychophysiological detection of deception with the Zone Comparison Test decision rule process in order to increase the accuracy of polygraph examinations.
Abstract
The modifications produced more correct decisions and fewer no-opinion (NO) decisions, with a small increase in the number of incorrect decisions when compared to the two one-stage models. Suggestions are offered for future research in this area. Two two-stage models for producing decisions following conventional physiological data scoring were proposed. Total score cutoff values were used to produce decisions during the 3T (Total) stage, with totals of -6 or less producing decisions of “deception indicated,” +6 or greater producing decisions of “no deception indicated,” and totals between these cutoffs producing a “NO” decision. During the 3S (spot) stage, scores assigned to individual question pairs were evaluated to produce decisions, in addition to total cutoffs. The assigned scores were totaled for each of three relevant-comparison question pairs in order to produce a spot score for each question pair. If the total score was -6 or less or if any spot score was -3 or lower, then a decision of “deception indicated” was produced. If the total score was +6 or higher and if all three spot scores were +1 or greater, a decision of “no deception indicated” was produced. If neither of these criteria were met, a decision of NO was made. The two-stage 3T3S model consisted of the 3T (total cutoff) stage, followed by the 3S (spot score) stage in resolving NO decisions. The stages were done in reverse order in the 3S3T model. Data from three laboratory and two field studies were evaluated in order to compare the accuracy of the two-stage models with the accuracy of models using only one of the two stages (3T or 3S). 9 tables, 2 figures, and 15 references