Validity of the Positive Control polygraph test using the field practice model

Abstract

Introduced a model of field practice that provides examinee choice and commitment in a laboratory setting to assess the validity of polygraph testing. 38 female undergraduates were tested with 1 repetition of a 4-item Positive Control Test (PCT), 2 repetitions of a 4-item Control Question Test (CQT), and 1 repetition of a 3-item Guilty Knowledge Test (GKT). The PCT, a new and previously unvalidated test format, obtained average accuracy of 73% for the examiner and 78% for a blind judge of the polygraph record. Similar average accuracy was obtained with the other 2 tests, but the PCT was less biased against detection of truth than the CQT and less biased against detection of deception than the GKT. Further results indicate that incentive to avoid detection may increase detectability of the deceptive, that a combination of the PCT and the CQT may be more accurate than either alone, and that number of repetitions of questions may be more important than chart minutes in increasing detectability with the CQT. (29 ref) (PsycInfo Database Record (c) 2025 APA, all rights reserved)