A polygraph or lie detector examination might best be described as a truth verification
examination. While all eminently qualified polygraph experts must always remain neutral
and not be swayed by someone’s appearance, age, gender or personality, each examiner
must be doing everything within their power to influence the person taking the test to have
a favourable result. Anyone and everyone can pass the examination simply by being
completely truthful about the issue being examined and do so during the pre-test
polygraph interview. Irrespective of what the person taking the test may have done, by
being truthful during the pre-test interview, it guarantees their successes in passing the
examination. For example, if someone was being tested for a theft at his or her place of
business, and they discuss this with the examiner, one of the relevant test questions might
be, “Other than what you discussed with me before this test, have you stolen any more of
the missing money or product?” It is our experience that since a wider margin of those
taking the polygraph test have favourable truthful responses, it might be best to refer to the
examination as a “Truth Detector” as opposed to ‘Lie Detector.” The word polygraph is from
the Latin, “Many Writings.” A modern day polygraph instrument evaluates multiple
physiological responses, thus, “Poly,” as in “Many” writings, graph.
What does the polygraph
procedure involve?
Once a person or company has scheduled an examination, a block of time is allocated to
properly conduct a pre-test interview, the examination itself, a possible post test interview
and occasionally, the preparation of a typed report which outlines the issue under
consideration, the relevant test questions, and the opinion of the expert who administered
the examination. The test itself is traditionally the component of the entire polygraph
examination process that takes the least amount of time. The purpose of the pre-test
interview is to garner as much information as necessary to prepare the test questions. It
also allows the examining expert the opportunity to explain the instrument itself, and to an
extent, what physiology is actually being recorded. Multiple issue tests should never be
conducted. For example, a standard series of test questions may contain many questions
about a singular issue….such as theft, arson, fidelity or child molestation. Yet, it would never
include both issues during the same examination. Typically, polygraph experts would ask a
client to explain the general nature of the test and specific information to formulate the test
questions. Clients that require testing of multiple issues should know that to accomplish
this type of testing, it also requires different testing sessions, generally on different days of
testing. No compound questions should be allowed and conjunctions are never allowed.
For example, your expert would never ask a question such as “Did you rob and kill John
Doe?” The reason for not asking such a question is that if deception to that question were
noted on the test tracings, the examiner would not know whether the person taking the test
robbed, or killed John Doe, or did both. We encourage all clients to allow us to assist you in
identifying the most critical issues in formulating the test question format.
The examination does not cause pain. There can be some slight discomfort with the
pressure in the blood pressure cuff, but since the actual chart time for each series of
questions is typically under three minutes, there is usually a slight numbness or tingling as
opposed to a painful experience. All test questions are reviewed with each person being
tested. Surprise questions are never allowed and we urge anyone who has agreed to
participate in this testing technique to terminate the test should any unrevealed questions
be asked during the test. Always remember, you control whether you take this test and you
may feel free to discontinue it at any time.
Any person that appears to have been drinking alcoholic beverages will be refused for
testing. Any person that appears to be physically unfit for testing because he or she has
used drugs, prescribed or otherwise will also be rejected if the examining expert feels that
they might interrupt the proper interpretation of the examination. Of course, polygraph
experts do not want you to stop taking your medication. Taking your prescribed medication
is important and does not mean that an effective and accurate test is not possible. In almost
all cases, successful completion of the test will be quite possible. We usually will be able to
identify anyone who has taken drugs or narcotics for the sake of getting high, or “low” as
the case may be, and your chart tracings will immediately identify whether or not you are a
suitable “subject” for testing.
All persons taking a polygraph/lie detector test will be provided with their test results.