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How does a Lie Detector Test work?

The lie detector test records manifestations of a person’s nervous system from at least three systems in the body whilst questioned about concerns of a specific issue, incident or event. The examiner will analyse the charts collected and render an opinion as to the persons truthfulness. A polygraph examination consists of four phases and will typically take between 2 to 3 hours to complete. The four phases of a polygraph examination are known as the pre-test, chart collection, test data analysis and finally the post-test phase. Pre-test phase. During the pre-test, the examinee is required to complete a consent form and medical form. The examiner will provide the subject with an overview of the examination and testing process and conduct a pre-test interview. The interview will provide the examinee with an opportunity to discuss their circumstance with the examiner in greater detail and to assist with test question construction. It is imperative to be truthful, open and honest with the examiner as any undisclosed information may affect the outcome of the test results. Chart collection phase. Sensors will be attached to the subject and the test questions reviewed.  The examiner will go onto administer and collect a number of charts. The number of questions asked and charts collected will vary depending on the format of the test used and the test technique. Test data analysis phase. On completion of the chart collection phase, the examiner will review the data collected and analyse the charts. An opinion of the examinee's truthfulness regarding the specific issue, incident or event will then be rendered. Post-Test phase. The examiner will provide the examinee with a verbal result and where appropriate the examiner will offer the examinee an opportunity to explain physiological responses to the questions presented during the test.

2018-03-08T14:57:38+00:00 March 8th, 2018|News Articles|0 Comments

What is a Lie Detector Test?

A lie detector test is also known or commonly referred to as a polygraph test or polygraph examination. It is one of the most powerful, robust and useful scientific tools in truth verification or the detection of deception regarding a specific issue, incident or event. The term “polygraph” derives from the Greek words poly (many) and graph (writing) “many writings”. A polygraph examination involves an in-depth procedure, using state of the art, computerised equipment and validated test techniques. During an examination, manifestations of a person’s nervous system are recorded from at least three systems in the body. Two convoluted tubes are placed around the upper chest and abdomen of a person to record respiratory activity. Two metal plates or disposable adhesive electrodes are attached to a person’s fingers to record sweat gland activity and a blood pressure cuff will record cardiovascular activity. A motion sensor will monitor general movements throughout the examination.  A finger plethysmograph may also be used to monitor blood volume. Voice stress tests should not be confused with a Polygraph Test. The two are completely different tests with voice stress testing working no better that pure chance (i.e. the accuracy of such voice stress instruments are similar to making a decision based on a flip of a coin). We therefore do not use it in our examinations. An examination should only be conducted by an experienced and trained polygraph examiner.

2018-03-08T14:54:01+00:00 March 8th, 2018|News Articles|0 Comments