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Numerical Scoring of Polygraph Charts: What Examiners Really Do

NCJ Number
141009
Journal
Polygraph Volume: 21 Issue: 4 Dated: (1992) Pages: 264-320
Author(s)
M H Capps; N Ansley
Date Published
1992
Length
57 pages
Annotation
An attempt is made to obtain information about what criteria polygraph examiners currently apply when they analyze sets of control question polygraph charts.
Abstract
Eleven white, male examiners participated in a detailed project of chart review evaluation and criteria identification. Evaluators were blind to case facts, scores, conclusions, and all demographic information. They did not know how the questions were worded, but control and relevant questions were identified by number. The examiners were required to review all 40 sets of charts. Additionally, the examiners were provided a form with a checklist to be used for chart analysis. The examiners were correct in their blind review of the sets of charts in 361 of 440 decisions. Examiners were correct in 135 of 187 decisions for truthful cases and in 226 of 253 decisions for deceptive cases. When examiners were asked to indicate criterion present in the decisionmaking process, there were 3,984 opportunities in each component to indicate one or more of the criterion present. In the respiration, suppression was indicated to have contributed to a decision of truth or deception 958 (24.6 percent) times followed by baseline change 435 (11.2 percent) times. Each of the other criterion (electrodermal and cardiovascular) were indicated as being involved in the decisionmaking process less than 10 percent of the time. 5 tables and 140 references