How The Polygraph Works? - The polygraph traces changes in physiological conditioning during questioning by use of various components attached to the subject:-  Pnuemograph - rubber tubes placed around the upper chest and abdomen record breathing and movement; Galvanic Skin Response - fingerplates placed across the ring & index finger of the right hand trace changes in skin resistance during testing; Cardiosphygmograph - similar to the pressure cuff a doctor uses, this component traces changes in blood pressure and pulse rate which occur whilst the test subject is responding to pre-agreed questions. Your body generates tracings on the polygraph charts which allow conclusions to be reached as to the subject's honesty regarding the issue.

Question Formulation - We only use the latest question techniques as are widely accepted in law enforcement throughout the USA. Our examiners work with the client to construct questions that cover the test issue. The latest techniques allow a maximum of three questions to the issue of concern. All questions are reviewed and pre-agreed with the client.

The Test Process - A test takes 2 hours or more and consists of pre-test interview, collection of charts and analysis of charts. A full written report on request to the signatory.

Pre Test Interview - During the pre test interview the examiner will explain how the polygraph works, discuss the issue that concerns you and develop all the questions to be asked on the polygraph test. This stage can take anything up from 45 to 90 minutes.

Collection of Charts -  During this phase the subject is attached to the polygraph sensors. The pre-agreed questions as developed during the pre-test interview are asked several times.  During this stage only the examiner and subject will be present.

Do nerves affect the results of a test? - No. It is expected that all polygraph test subjects will be nervous, whether they intend to be truthfull or not. Examiners look for responses over and above the examinee's normal heightened level of anxiety.

Can someone beat the test? - The polygraph is a medical instrument that records changes in a person's autonomic reactivity whilst they answer the questions. An experienced examiner will identify an examinee attempting to alter the outcome of a test.

Test Accuracy - The American Polygraph Association (APA) has gathered over 200 studies on the subject. Based on twelve separate studies involving 2174 actual cases since 1980. Evidence suggests that qualified polygraph examiners are 98% accurate in their overall decisions.  (Refer: Ansley, N 1990 The Validity and Reliability at Polygraph examinations in real cases)