A Comparison of Accuracy Rates Between Detection of Deception Examinations Using the Polygraph and the Computer Voice Stress Analyzer in a Mock Crime Scenario.
Final rept. Dec 94-Aug 96,
DEPARTMENT OF DEFENSE POLYGRAPH INST FORT MCCLELLAN AL
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The accuracy and consensus of decisions rendered between examinations administered using the traditional polygraph instrument and the Computer Voice Stress Analyzer CVSA were examined. One hundred twenty subjects were given detection of deception examinations either on the polygraph instrument or the CVSA. Subjects were divided into two groups, with one group participating in a mock theft and instructed to be deceptive about their participation in that crime. The remaining group was told that a crime had been committed, but they did not participate in any way. This group was instructed to be truthful about not being involved in the theft. Half of each group of subjects were tested in a Psychophysiological Detection of Deception PDD examination using the polygraph instrument and the remaining half were tested using the CVSA instrument. Groups were counterbalanced for gender. Six blind scorers, three trained in polygraph use and three trained in use of the CVSA, independently rendered decisions for subjects examinations. Neither group of blind scorers achieved overall accuracy rates better than chance levels. A significant interrater agreement among the three blind examiners within each instrument type was found using the Kappa statistic for multiple raters p less than .05.