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Reliability of the Empirical Scoring System with Expert Examiners

NCJ Number
236806
Journal
Polygraph Volume: 40 Issue: 3 Dated: 2011 Pages: 131-139
Author(s)
Raymond Nelson; Benjamin Blalock; Marty Oelrich; Barry Cushman
Date Published
2011
Length
9 pages
Annotation
This study investigated the reliability and accuracy of the Empirical Scoring System (ESS) with experienced examiners.
Abstract
Monte Carlo statistical methods were used to calculate confidence intervals for the reliability and accuracy of the ESS with a cohort of 25 experienced examiners who scored a small sample of 10 confirmed psychophysiological detection of deception (PDD, polygraph) exams that were conducted using the Federal ZCT format. Fleiss kappa showed a substantial agreement between the numerical scores of the study participants (k = .61, .54 to .68) and decision agreement that was significantly better than chance with a mean rate of decision agreement of 95.4 percent, excluding inconclusive results. Bootstrap Monte Carlo methods were used to calculate the accuracy profile and statistical confidence intervals of the ESS scores from the experienced examiners. The authors recommend continued interest in the ESS as an evidence based model for manual test data analysis in field polygraph settings and future research. (Published Abstract)