POLYGRAPH TEST FAQ

Generally, any person who desires to verify their truthfulness regarding a specific situation or incident is a good candidate for a polygraph. Any person who intends to lie or withhold any relevant information about the issue under consideration should most certainly not take a polygraph test.

 U.S. Government studies have concluded that when a qualified examiner conducts the test properly, the polygraph exam is 95 percent accurate.The latest research by the Department of Defense has shown a professionally administered polygraph examination to be approximately 98% accurate.It is the most accurate means available for determining the truth or deception of a person answering a direct question in a court.

No. While blood pressure is one of the physiological reactions measured, it does not affect the accuracy of the polygraph test.

Contrary to what many think, the use of drugs and/or alcohol will not assist someone to beat a polygraph test. Polygraph examiners utilize certain procedures during a polygraph test ensure that each person taking a test is responding naturally throughout the testing procedure. If you are taking any medication you need to inform the polygraph examiner prior to beginning the test. Physiological affects that drugs have on people are immediately seen in polygraph chart tracings. Irregular physiological recordings must be satisfactorily explained.

No. Everyone who submits to a polygraph is nervous but for many different reasons.

Innocent:

Although most truthful persons believe they should pass a polygraph test, they are often worried that something might go wrong. This doubt will cause the person taking the test to experience a heightened sense of anxiety about the test itself. This kind of nervousness is normal and has no effect on the positive outcome.

Guilty:

Guilty persons are nervous also, but for a very different reason. The guilty tend to be afraid they are about to be exposed. When a guilty person’s bad actions are exposed, that guilty person will frequently suffer some negative consequence as a result of having done that bad thing. Being nervous about being exposed or about being punished for having done something bad or wrong is also normal but it tends to help expose the guilty and deceptive.

When a person perceives a threat, the body reacts to the threat. This is referred to as the “fight or flight” reaction, as the body readies itself either to fight off the threat or to flee. When a person tells a lie, it is because for some reason, the truth constitutes a threat to that person.

Consequently, certain physiological reactions take place in the person’s body which he/she cannot control and which can be measured by the polygraph (See “Human physiology: a basis for the detection of deception” on our web site for more details).

A polygraph instrument collects physiological data from at least three systems of the human body. Pneumograph tubes are placed over the examinee’s chest and abdominal area to record breathing patterns and finger plates are attached to the fingers to record sweat gland activity.

A blood pressure cuff will record cardiovascular activity.

The reactions are charted by the polygraph instrument and reflected on charts printed from the recordings.

 Yes, the test is completely confidential between the examiner and the person taking the test. The person taking the test may also elect to provide the results to another person or persons.

In each case a polygraph examiner should always tell the person taking the test how they did on the test. In cases where a person taking a test has a problem in a question, the examiner should bring that problem question to the attention of the person taking the test so as to give them a specific opportunity to resolve that problem.

A written report including the relevant questions and the examiner’s opinion will be provided upon request, usually with 24 hours.

 The number of questions that can be asked on a polygraph examination is limited. The number of questions the examiner can ask will depend on the type of test format used by the examiner.

• A typical polygraph examination will include periods referred to as a pre-test phase, a chart collection phase, post- test phase and a test analysis phase. This procedure usually takes one to one and a half hours.

• In the pre-test phase, the polygraph examiner will complete required paperwork and explain the theory of the polygraph in an understandable way to the examinee. The examinees will be given the opportunity to discuss their roles or perceptions regarding the case under investigation and provide relevant information. During this period, the examiner will discuss the questions to be asked and familiarize the examinee with the testing procedure.

• During the chart collection phase, the examiner will administer the examination and collect a number of polygraph charts. No questions will be asked during the examination that have not been discussed and reviewed with the examinee.

• In the post-test phase, the examiner will analyze the charts and render an opinion as to the truthfulness of the person taking the test. The examiner, when appropriate, will offer the examinee an opportunity to explain physiological responses in relation to any questions asked during the examination.

A professionally administered polygraph examination should normally take between 2 and 3 hours to properly administer from start to finish. A professional Polygraph examiner will go through several structured test phases to ensure that it will work accurately. The pre-test phase, the test phase, and the post-test phase. During these phases the examiner and the person taking the test will become very involved in discussing the details of the test and the manner in which the questions are presented Persons taking polygraph tests often feel the need to fully explain their circumstances during the pretest This is not discouraged by the examiner. The examiner should also attempt to answer each question presented to him by the person taking the test.

Each and every question to be asked a person taking a test is discussed in detail with that person in the pretest phase prior to the administration of any polygraph test charts. No professional polygraph examiner will ask a surprise or trick question on a polygraph test. It is not only unethical for an examiner to ask a surprise question but responses to these types of questions do not accurately indicate truthful/non-truthful results.