Frequently Asked Questions
How accurate is a polygraph test?
Considerable scientific research has demonstrated that the pattern of physiological changes during a polygraph test provides the basis for making highly accurate inferences concerning truth or deception. The vast majority of scientific evidence supports the reliability and accuracy of comparison question tests for assessing credibility.
In the past 75 years, over 250 studies have been conducted on the validity, accuracy and reliability of polygraph testing (American Polygraph Association 1996 Polygraph Issues & Answers). Based on twelve separate studies involving 2,174 real cases since 1980, evidence suggests that qualified field polygraph examiners are 98% accurate in their overall decisions (Ansley, N. 1990 The validity and reliability of polygraph decisions in real cases). This level of confidence is well within the guidelines for scientific measurements in other fields.