Frequently Asked Questions

How do I book a test?

To book a polygraph test NOW simply click on the Book a Test button and complete your details and our examiner will be in contact with you shortly. Simply tell the examiner the purpose of the test and where you live. We will then coordinate your quotation, polygraph examination, time and date.

How much does a polygraph test cost?

Every case is different. Some polygraph tests are straight forward whilst others are more complex and time consuming. Simply click on the Book a Test button and complete your details and our examiner will be in contact with you for pricing.

What can’t a polygraph examiner ask me?

The examiner may not ask you any questions relating to your
• religious beliefs or affiliations (unless specifically relevant to the job)
• beliefs or opinions regarding racial matters (except to the extent that any such biases could interfere with one’s ability to fairly and objectively perform his or her job)
• political beliefs or affiliations
• beliefs, affiliations or lawful activities regarding unions or labor organizations
• lawful sexual preferences or activities

Can someone beat the test?

People don’t beat a polygraph test they beat the examiner conducting the test. This is why it is imperative to ensure that the examiner conducting the test is certified and qualified.  A polygraph is simply an instrument that records changes in autonomic reactivity when confronting a given stimulus (question). If a person engages in behaviors that are designed to distort the polygraph tracings then it is the job of a competent and qualified examiner to identify and determine when this is occurring.   In most cases it is easy for a qualified examiner to determine when an examinee is attempting to influence the outcome of the exam. Although some parameters can be consciously controlled these are usually easily detected.  Typically truthful examinees are cooperative and follow instructions whereas deceptive examinees will attempt to engage in certain behaviors in an effort to distort the tracings. When such behaviors are identified three verbal warnings are given. If this behavior continues the test is stopped and a Purposeful Non Cooperation (PNC) result is returned.

What should I look for when seeking a polygraph examiner?

It is important that you choose a polygraph examiner who has been professionally trained, accredited and certified. Every qualified examiner must reach certain competencies before certification can be awarded. After training, each qualified examiner must serve an “internship” whereby their work is quality controlled and evaluated to ensure that the appropriate testing formats are used and that questions are properly formulated according to current testing methodology.

If you have spoken to someone who represents themselves as a qualified polygraph examiner ask them where they trained and what polygraph qualifications they hold.

Do nerves affect the results of a polygraph test?

No. A polygraph records changes in blood pressure, pulse rate, pulse strength, galvanic skin conductivity and reactivity (sweat gland activity), and changes in pneumographic patterns.
It is expected that all people who undergo a polygraph test will be nervous whether they intend to answer questions truthfully or not. As a result we calibrate the instrumentation to work off that heightened level of nervousness or anxiety. An examiner will look for action specific responses over and above the examinee’s heightened level of nervousness or anxiety.  Typically an examinee remains nervous throughout the entire testing process not at one individual question. If nerves affected the result of a polygraph test then nobody would ever pass a test!

How many questions can be asked?

One of the major misconceptions about polygraph testing is that people think several questions concerning various issues can be asked in the one test. This is not the case. By asking several questions relating to separate issues only diminishes the accuracy of the testing process which is the last thing that you would want to have occur. Reducing the accuracy of the testing process defeats the purpose of having the test conducted in the first place.
Introducing several issues in the one test creates a situation where questions start competing against each other which weakens the accuracy of the test. This situation should be avoided at all costs. Multiple issues can be tested but they need to be conducted on separate tests (discounts apply for multiple tests). A qualified examiner however can formulate a single question that will often cover the central theme or major issue.

I have heard polygraph testing done on the radio and seen it on some TV shows. Are these tests real polygraph tests?

No. Many of the polygraph tests seen on television and conducted for radio promotions are often not real or validated tests. A polygraph test cannot be conducted in a few minutes. A validated polygraph test will usually take two to three hours of which several procedures need to be adhered to. Any polygraph test that hasn’t incorporated a pretest is dangerous and prone to errors.

How accurate is a polygraph test?

Considerable scientific research has demonstrated that the pattern of physiological changes during a polygraph test provides the basis for making highly accurate inferences concerning truth or deception. The vast majority of scientific evidence supports the reliability and accuracy of comparison question tests for assessing credibility.
In the past 75 years, over 250 studies have been conducted on the validity, accuracy and reliability of polygraph testing (American Polygraph Association 1996 Polygraph Issues & Answers). Based on twelve separate studies involving 2,174 real cases since 1980, evidence suggests that qualified field polygraph examiners are 98% accurate in their overall decisions (Ansley, N. 1990 The validity and reliability of polygraph decisions in real cases). This level of confidence is well within the guidelines for scientific measurements in other fields.

How long does a polygraph test take?

Depending on the complexity of the case and the issues being tested a polygraph test usually takes up to two hours. In most cases a verbal result is available after testing followed by a typed report.

How does the test process work?

The science of polygraph testing is based on far more than the technology of the polygraph instrument. The interview skills of the examiner are paramount in ensuring an effective testing process free of ambiguity or doubt.  
Firstly the Examiner must obtain a comprehensive brief which identifies the circumstances, issues, allegations and facts in dispute. 
Secondly, the examiner reviews the material, and formulates test questions in such a way as to elicit clear and complete responses. It is critical not to ask questions which can result in partial answers. In this stage the material gathered from the Pre-test brief is broken down into its component parts and matched to the appropriate questions. 
Thirdly, the examiner takes the participant into the testing phase. This is where the sensors are attached to the examinee and the recording process commenced. The questions are read to the examinee several times during the recording process. Typically a minimum of three charts are recorded. After each question is asked a 25 second period follows whereby the instrumentation records autonomic responses to each.  Finally the data collected from the polygraph charts is printed and the results numerically scored. The test results are then given to the relevant parties. Final results are possible. Truthful, Deceptive, In order to reduce distractions for the examinee polygraph exams are conducted in private with no other persons permitted in the examination room (other than an interpreter if required).

What does a polygraph records?

A polygraph test records physiological responses whilst the examinee answers a series of questions. Polygraph techniques are derived directly from basic scientific principles and research in psychology and human psychophysiology. Physiological measurement techniques for the detection of deception have been developed and subjected to scientific evaluation for almost 100 years. The most commonly used polygraph tests are based on widely accepted scientific principles. It is well established that certain stimuli, such as questions to which a person is lying during a polygraph test, produce involuntary changes that are controlled by the autonomic (sympathetic & parasympathetic) nervous system. These reactions include increased skin conductance (palmar sweating), increased blood pressure and decreased respiratory activity.

Are polygraphs admissible as evidence of wrong doing?

The case of Harmse v Rainbow Farms (1997): WE 1728 – Commission for Conciliation, Mediation and Arbitration of South Africa (CCMA) – set an important precedent in South African labor law.

Its finding allowed for businesses to use polygraph technology in the workplace in a responsible and sensible manner. There are rules that need to be adhered to regarding the use of polygraphs, including the stipulations of the Bill of Rights as contained in the Constitution, of which the most important rule is that an employee is not compelled to submit to a polygraph examination.
The examination must always be voluntary and questions regarding religion, sexual orientation, political affiliation and union membership are not allowed and the individual has the right not to self-incriminate. The main benefit of polygraph examination is that critical elements of information can be quickly confirmed or rejected. Cognizance should be taken of the fact that the result of a polygraph examination may not be regarded or used as the sole source of evidence. Therefore, if the polygraph result is supported by other probable evidence, it is generally accepted as evidence by the CCMA and bargaining councils. In this regard, a large number of decisions have been handed down by the CCMA and the Labor Court, where polygraph results have been accepted into evidence.

However, there have been instances where the presiding Commissioner has refused to allow polygraph evidence to be accepted. This may be regarded as irregular, and could be considered as grounds for review. It could be argued that using a polygraph in a working environment is a drastic measure to deal with disciplinary issues. However, if used correctly, the validity and reliability of the polygraph technique could be in excess of 98%.  For your benefit the following links to articles related to employee-theft have been included:

© No Lies Polygraphs [PTY] is a member of the following associations, South African Professional Polygraph Association as well as the International Society of Polygraph Examiners.
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