Polygraph Testing 101

What is the procedure for polygraph testing? It varies, but the following is an example of how a typical test might go:

You enter the room for the polygraph test, and are told to wait. You can assume at this point that the procedure has begun. You are probably already being watched for signs of nervousness (sometimes by hidden camera now). You are also getting anxious about the test. The professional manner in which the machinery is prepared makes you feel that it really works, which makes you a more appropriate subject -- belief in the test is important.

Then you are given a pre-test interview, or a questionnaire to fill out. It has many of the same questions that you will be asked during the test. This interview or questionnaire may not be on the same day as the polygraph exam.

Just prior to the test, the administrator explains the polygraph exam to you. She tries to get you to relax, and may tell you that it is normal to be nervous. She may also say that it's normal to have things come up which you forgot to mention in the questionnaire. She says that many of these questions will be asked now without the polygraph, just to clear things up, and that any sudden recollections of things you forgot to say will not be held against you.

She probes deeper into the questions, and tries to get you to admit to anything relevant. For example, if this is a matter of employee theft, she may ask if you knew about the theft, or knew who was involved. She will remain calm through any admissions, to encourage you to feel comfortable saying more.

Then the operator will ask a few general questions, such as "Is there anything else you want to say before the test starts?" She might ask if there is anything you want to add to your answers, or if you were hiding anything from her. The idea is to clear your mind of any small issues prior to the test, and, of course, to get any admissions she can.

Now you get an explanation of how the polygraph works. She explains that the polygraph tracks physiological responses you have when you are asked a question (and when you answer it). She tells you that they are all "yes" or "no" questions, and may mention that the results are not admissible in court.

There will be no "surprise" questions, you are told. In fact, you will know the questions to be asked before the test, and they will be asked in the same order during the test. This is done on purpose, for better tracking of physiological responses. In this way, you'll know when a "problem" question is coming, and the polygraph will more accurately measure your response to it--so says the theory of polygraph testing.

She explains that "baseline" questions will be asked at the beginning. These are questions that the operator and you both know, like your name, place of employment, and perhaps a few other simple questions. She tells you that normally your baseline responses rise as you are asked a question, and fall after you answer.

She may go deeper into the process, explaining how knowing that a "problem" question is coming, your baseline will rise during subsequent questions. You will be anticipating it, and then, once it is asked, there will be a more dramatic drop in the baseline upon answering it. This is from the normal release of tension we feel when an anticipated event is over, and this is measured by the polygraph machine.

Why is this explained to you (if it is)? Because hearing how this works actually makes you more susceptible to the anticipatory build-up of tension, and the measurable "relief" once you answer. It also makes you more of a believer in the polygraph test itself.

Once you're hooked up to the machine, the tester may do an "Acquaintance Test." This used to be called the "stim" test (stimulation test), and requires that you tell a deliberate lie. For example, the examiner may write a number "6" on a card and place it in plain sight, on a wall or on the table between you both. Then the examiner ask you "Is it a 1?" and then, "Is it a 2?" and so on, with you answering yes (lying) each time.

Afterwards, she tells you that she could detect when you were lying (of course). She may then calibrate the machine as you watch. This is all a show, to convince you that polygraph testing really works. If you want to see the tester squirm, suggest that you write a number on the card out of sight, and the tester determine what it is from your responses -- without seeing it. On second thought, don't actually try this or you'll just anger the examiner.

Continues here... The Polygraph Machine

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