Lie Detector Testing is subdivided into three different stages:

The Pre-Exam Interview, The Polygraph Exam, and The Post-Exam Interview. This is typically administered by a professionally trained and certified polygraph examiner or polygraphist using a computerized, state-of-the-art polygraph technology in a comfortable and climate-controlled office.

Pre-Exam Interview

The first stage of the polygraphic lie detection test is the Pre-Exam Interview. During this stage, the purpose of the examination is made clear to the examinee. This stage is where the examinee is advised of their rights, including the constitutional rights to obtain a legal counsel or express unwillingness to undergo the examination. It is also during this stage that the examinee is asked for their version of the story and made aware of the questions as well as the procedure and instruments that will be used in the actual polygraph examination. Once all of these are done, the polygraph components—usually consisting of sensors for collecting, measuring, and recording physiological data—are attached to the examinee.

Polygraph exam

The second phase of the lie detector test is the test phase, otherwise referred to as the Polygraph exam. During this part, the examiner establishes the baseline readings or, for the examiners, the tonic. The examinee is then asked about known questions, including but not limited to personal questions like the name or the age, all in the form of questions answerable by Yes or No. The examinee is also asked about character questions, to which most examinees feel uncomfortable answering due to its nature which may be personally or socially unacceptable. Though the questions are diverse in nature, there are standard limitations to the type of questions that are asked during the test, which should not be personal or intrusive. These types of questions include beliefs—religious, political, or racial, and sexual orientation and activities. The Polygraph Exam stage is when the actual test occurs. With the questions reviewed and formulated during the Pre-Exam Interview, the examinee is asked to answer with a Yes or a No. These questions are asked for a minimum of three times with a pause in between each one for the duration of this particular stage of the lie detection test.

Post-Exam Interview

Immediately after completion of the Polygraph Exam, the third and the last portion of the Lie Detector Test, the Post-Exam Interview, follows. During this phase, the examiner does the job of analyzing, interpreting, and evaluating the physiological data gathered during the testing procedure. It is during this stage that the examinee is asked to explain about their reactions noted from the charts during the Polygraph Exam phase.

Since the polygraphic lie detection test is designed in such a way that the physiological changes in a person are measured and recorded both for observation and comparison, the controversy about its veracity has remained. The underlying theoretical idea that changes in the pattern of psychophysiological reaction is exclusive to deception is questionable for most critics. Dr. Saxe and Israeli psychologist Gershon Ben-Shahar even went as far as saying that validity studies, such as the polygraphic lie detection test, are impossible to conduct properly.

It is true that lie detector tests are not infallible. However, as Nietzsche once said, “There are no facts, only interpretations.” With the benefit of over 250 studies regarding the accuracy of lie detector testing over the last 25 years, it has survived claims of inaccuracy from polygraph test critics and has remained one of the most effective ways of truth and lie verification.

Polygraph History

Since its introduction in 1921, lie detector testing, as well as its accuracy, has always been a controversial issue in both the scientific and public domains. In fact, despite the popularity that it has gained in the cultural realm over the years, the veracity of polygraph tests continues to plague our endless search for truth.

Xenophanes once said: “Pure truth no man has seen, nor shall ever know.”  While there may be some truth in this statement, man’s search for truth did not waver. Since the beginning of civilizations, man has struggled to distinguish the lies from the truth of his very existence and since then, techniques have been invented and reinvented to seek out the truth and weed out the lies.

One of the most prolific truth-seeking techniques that man has developed is the association of truth and lies to the physiological reactions exhibited by a person in the face of deception. Primitive as it is for some people, this simplistic technique has been used through the years, and up to this date, it has remained the most important consideration in truth-seeking examinations. This led to the modern-day polygraph or lie detector test.

As in every truth-seeking process, the polygraphic lie detection process starts with research. Relevant information on the examinee and the facts about the case surrounding the examination are gathered and studied. Action plans are also created before the actual testing is conducted. Once completed, the actual lie detection examination can start.


10 Things you need to know before taking a Lie Detector Test
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