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First Look at Electrodermal Monitoring During Polygraph Pretest Interviews: The LPI Experience

NCJ Number
Polygraph Volume: 42 Issue: 2 Dated: 2013 Pages: 72-79
Donald J. Krapohl; Felipe Malagon Bolanos; Manuel Antonio Novoa Bermudez
Date Published
8 pages
This study examined the value of physiological data during polygraph testing for pretest interview assistance.
While the value of physiological data during polygraph testing has been subject to repeated research, investigations regarding the usefulness of polygraph data for pretest interview assistance have not been previously published. Five experienced polygraph examiners conducted a total of 92 field screening polygraph examinations, and during the pretest interview the examinee's electrodermal activity was monitored, as well as movements via a motion pad. The examinees were not told of the real time-monitoring. Dependent measures included examiner attitudes regarding the usefulness of these data to the interview process, and the proportions of polygraph results for DI, NDI, and Inconclusive compared to pre-study levels. The findings suggest that monitoring phasic EDRs during the pretest interview had only a modest benefit with selecting DLCs, no effect on garnering pretest information, and none on the proportion of No Significant Response (NSR), Significant Response (SR), and No Opinion (NO) results as compared to historical averages. Suggestions are offered for future lines of research. (Published Abstract)