Polygraph (lie detector test) FAQs – SPL Investigative Services
 

Frequently Asked Questions about Polygraph, sometimes called Lie Detector Tests

You have been asked to take a polygraph exam or lie detector test. For the majority of people, polygraph testing is a new and often frightening experience. We have prepared the following information to help you prepare for the exam and to provide answers to frequently asked questions.

What is a Polygraph Examination?

The polygraph examination consists of the use of a professionally manufactured certified scientific instrument designed specifically to record physiological changes that occur in the human body. The examiner looks for those changes consistent with truthfulness or deception and forms an opinion about your truthfulness based upon

What does the Polygraph record?

Your polygraph exam will be given using a Layfette Computerized Polygraph Instrument with the state of the art, up to date, current software. During the polygraph exam we will record your respirations, the ability of your skin to conduct or resist electricity (Electrodermal Activity, EDA), cardio vascular activity and monitor movements within your body.

What if I am nervous will this affect the polygraph results?

Without a doubt, this is one of the most frequently asked questions regarding taking a Polygraph exam. Thankfully the answer is “No”. Everyone is nervous to some degree and the polygraph is not looking for bodily changes associated with nervousness. General Nervous Symptom (GNS) is expected. Polygraph is a continual recording of our physiology which can show that nervousness is present while being examined. Polygraph will capture and record internal physiological changes within our sympathetic and para-sympathetic nervous system during the specific time of the psychological stimulus (questions asked). At no other time is change measured and scored.

How does a Polygraph work?

The Polygraph records physiological changes that occur in the human body. These changes are evaluated based upon changes that occur when questions are asked. Most of us can remember a time when we lied to our parents or other significant person. We could feel the changes in our bodies. When we evaluate the polygraph charts, we measure different physiological changes during a specific measure of time indicative of lying or truth. Lying and/or being honest makes us feel completely different from just being nervous.

How long does a Polygraph Exam take?

A valid professional polygraph exam should take 2 to 3 hours or longer depending on the details involved in the case.

How are these recordings made?

The recordings of your respiration patterns are accomplished using two components, one that goes across the chest and the other across the abdomen. The ability of your skin to conduct or resist electricity is recorded by placing two electrodes on the fingers or using electrode pads on your palm. Cardio Vascular activity is recorded using a standard blood pressure cuff placed on either the forearm or upper arm.

Will the exam hurt?

The only thing felt during the polygraph exam is the blood pressure cuff. When your blood pressure is taken by a doctor, the cuff is inflated to approximately 200 mm hg then the pressure is slowly let out over several seconds. During the polygraph the examiner will inflate the cuff to approximately 60 mm hg and keep the pressure constant at that point. As the exam progresses, the cuff may feel slightly tighter do to your personal blood volume and flow however the cuff is only inflated for three (3) to four (4) minutes at a time during the collection of your physiological recordings. If there is any discomfort at any time make sure you communicate it to the examiner.

Are there different types of “lie detectors?”

There are several types of polygraphs on the market today. Each instrument records the same basic psychophysiological data as described above. The actual recording may be made using ink and paper or by a computer.
There are those who claim to detect lying using “voice stress.” It is important to know that every published scientific research project assessing the “voice stress” technology has found the exam to be accurate between 47% and 52% of the time. The scientific community does not recognize “voice stress” as an accurate process to detect truth or deception.

How accurate are polygraph exams?

There have been several published scientific studies of the accuracy of polygraph testing. The overall accuracy of a properly administered polygraph exam using a validated and correct technique is between 90% and 94%.

What will happen during the actual polygraph exam?

When you first meet with the examiner he will lead you to the polygraph room. The terms and conditions of the exam will be explained and you will be asked to sign a statement indicating you understand and accept the terms and conditions for testing.

The examiner will then collect basic data about you and the purpose of the exam. Questions about health and substance abuse may be asked. These questions help the examiner to determine if any health problems exist that could have an adverse impact on the testing process.

Once the preliminary questions have been asked and information obtained, you and the examiner will then discuss the matter under investigation. During this part of the exam, you are given the opportunity to explain what you know about the matter under investigation. You and the examiner will discuss the allegations (specific issue testing).

After discussing the matter under investigation, you and the examiner will discuss questions to be asked during the data collection process. You will be informed of the exact wording of each and every question to be asked during the exam.

Are personal questions asked during a polygraph examination?

During the testing process, you may be asked personal questions that relate specifically to the matter under investigation. If you have concerns about the need to make a specific inquiry, ask the examiner, who will explain the purpose of the inquiry.

What outcomes can I expect from the polygraph exam?

At the conclusion of the exam, the examiner will review the data and numerically weigh the reactions. The opinion of truthfulness or deception is based solely on the numerical scores. Finally, the examiner may use a computer algorithm to analyze the data, and either support or question the numerical score. Final results are the responsibility of the examiner.

Will I know my results when I leave?

After the examination is completed the examiner will conduct his analysis explained in the above question. Upon his or review the results should be explained to you. Also what you should be aware of is most reputable examiners will have a quality assurance procedure in place which indicates that your examination results could be subject to being reviewed and confirmed by another professionally trained examiner prior to be the official result.

How do I schedule an examination with your firm?

1.   Call the office number, if there is no answer please leave a message with your contact info and we will get back with you, most often within a couple of hours.

2.   Once you’ve decided to use our firm we require a $250.00 booking fee in advance to secure a time slot for your examination. This fee is deducted from the total fee, which is to be paid in full before or on the day of the scheduled examination.  Booking Fee is billed through PayPAL and there is a small additional processing fee.

NOTICE:
The booking fee is non-refundable, you are allowed to re-schedule the examination due to illness, however, this must occur before 24 hours of your scheduled time or earlier.  Cancellation inside this 24 hour period will result in forfeiting the booking fee and will result in full invoicing for examination if not rescheduled.

3.   All No Shows will be invoiced for full fee.