The polygraph, also known as the psychophysiological detection of deception is a three phase process that includes a pre-test interview, an in-test data collection phase, and a test data analysis phase.
In the pre-test interview, the polygraph examiner determines that the examinee will be a suitable test subject and asks the examinee questions related to the test topic, which assists in developing the test questions. The examiner should also explain how polygraph works and all of the components that will be attached to the test subject.
During the in-test data analysis phase, components attached to the examinee record cognitively generated physiological responses in respiration, heart rate, sweat activity and blood flow when each question is asked.
In the test data analysis phase, the examinee’s responses are compared and scored using validated rules to permit decision accuracy.