Polygraph testing has been shown to be very accurate – with between 85% and 95% correct results – but errors do sometimes occur. There are many reasons why this can be the case, such as failure to properly prepare the test subject for the exam, improper question formulation, or a misreading of the physiological data on the polygraph charts.

When an error occurs, it is called either a “false positive” or a “false negative.” A false positive means that a truthful test subject is reported as deceptive, and a false negative means that a deceptive test subject is reported as truthful.

It is very unlikely for a test subject to change a result from “deceptive” to “truthful,” and most attempts to deceive an exam will result in an inconclusive result. The best way to ensure that your exam is accurate is to disclose any psychological or physical conditions you have. The examiner will be aware if it is possible for the condition to affect the results and can take it in account when administering the test.

Examiners recognize that any error can be damaging, so they are trained to look for attempts to control breathing or heart rate, impairment due to drugs or alcohol, or other factors that may affect results upon meeting the subject and during the pre-test. Additional protective procedures that are taken to ensure an unbiased exam include:

• an assessment of the examinee’s emotional state
• medical information about the examinee’s physical condition
• specialized tests to identify the overly responsive examinee and to calm the overly nervous
• control questions to evaluate the examinee’s response capabilities
• factual analysis of the case information
• a pre-test interview and detailed review of the questions
• quality control reviews

If you believe that an incorrect reading was given, you have recourse. First, you can request a second examination be made or retain a different examiner to get a second opinion. You can also file a complaint with the state licensing board (if your state has one) and a complaint with the Department of Labor under EPPA. Additionally, if the polygraph examiner is a member of the American Polygraph Association, you can request the assistance of the organization.

Sources:
American Polygraph Association
The Polygraph Guy – FAQs

If you do a quick search on the internet to find out the accuracy of polygraph testing, you’ll find a wide range of figures – as low as 61% and as high as 100% – although most reputable sources will report somewhere between 85% and 95%. So why is there such a variation in the figures reported?

For one, the studies are conducted differently. Some polygraph testing methods have proven more effective than others, yet some studies include all types of approaches, even those that may be considered out-dated, in their results. Another factor that can affect the level of accuracy includes the level of training the polygraph examiner has received.

But one of the biggest reasons for the variation in the figures is how the results are calculated. Critics often classify inconclusive tests as “errors,” but an inconclusive result simply means that the examiner was not able to make a definite diagnosis, meaning that he or she could not say for certain whether or not the test subject was lying. Most often in these cases, a second polygraph exam is done at a later time.

To understand how this can affect the accuracy rates that are reported, consider this example: 10 polygraph exams are given, and the examiner is correct 7 times, is wrong 1 time, and has 2 inconclusive results. If you consider the 8 definitive results, 7 were correct, giving you an accuracy rate of 87.5%. But if you consider the inconclusive results to be errors, then the accuracy rate drops to 70% – with 10 exams and 7 correct decisions.

Here are a few figures from reputable studies to consider:

• The National Academy of Science’s 2003 analysis of the 30 most recent polygraph data sets found an overall accuracy of 85 percent, and their analysis of seven field studies involving specific incidents found a median accuracy of 89 percent.
• The Journal of General Psychology looked at 41 criminal cases in 1996 and found that control-question tests were 93 to 96% accurate.
• In a survey of police agencies in the United States, over 90% expressed either moderate or high confidence in their polygraph screening program, and 80% of them reported that in their experience the accuracy of the testing ranged between 86% – 100%.

Even though polygraph testing is very reliable, there are sometimes errors, and some people are concerned that those being examined can use methods to “beat” the test. There are many steps that polygraph examiners take to ensure that this is not the case, which I will discuss in my next blog.

Sources:
American Polygraph Association
Telling the Truth about Lie Detectors – USA Today

If you are looking for a polygraph expert, one of the first things you should look for is that they have a membership with a professional organization. This is important because in many states there are no laws on licensing polygraph examiners, so that means anyone can buy the equipment and claim to be an examiner. But just having a machine isn’t enough to get accurate results. You need a trained professional who knows how to appropriately administer the test and evaluate the results.

As a member in “good standing” with these professional organizations, polygraph examiners are required to continue their education, which means they will be up to date on the latest technological developments, and must pass a criminal background check. Additionally, the organizations set up rules and regulations for how the polygraph is conducted and a code of ethics which members must follow.

American Polygraph Association (APA)

Established in 1966, the APA has grown into the leading professional polygraph organization in the world with more than 2,800 members who administer hundreds of thousands of exams every year. Their mission is to provide “a valid and reliable means to verify the truth and establish the highest standards of moral, ethical, and professional conduct in the polygraph field.” To become a member, you must complete hundreds of hours of coursework at an approved school as well as an internship. Once you have joined, you must engage in annual continuing education and training.

National Polygraph Association (NPA)

Dr. Chris Gugas, who started his polygraph career with the OSS during World War II, founded the organization in March of 1989, and the first national seminar was held by the group in 1990. The organization began with the mission to overturn the 1988 federal decision known as the Employee Polygraph Protection Act, but grew into something more than that, and they are pledged to “identifying and eliminating any unqualified persons from our profession.” Today they work to improve the capabilities of their members by promoting education, research, advanced training, and by shared experiences. Members are required to complete training at an approved school and must participate in continued education after joining.

American Association of Police Polygraphists (AAPP)

In 1976, William Taylor, then the commander of the Texas Department of Public Safety polygraph unit, saw the need for a national organization of police polygraphists. Today the organization conducts seminars for law enforcement polygraph examiners and requires its members to participate in continuing education.

Maryland Polygraph Association (MPA)

Like national organizations, local polygraph organizations such as the MPA offer opportunities for examiners to stay up to date on the latest developments in polygraph science and connect with other examiners nearby. Membership for the MPA is open to anyone who qualifies under the American Polygraph Association guidelines.

Sources:
American Polygraph Association
National Polygraph Association
American Association of Police Polygraphists
Maryland Polygraph Association

If you are looking for a polygraph examiner, one of your primary concerns is likely the cost. You will find professionals offering a wide range of prices, but generally a specific-issue polygraph exam costs between $500 and $1,500.

Fees charged by the same polygraph examiner can vary based on the complexity of the issue being tested, the type of test that will be conducted, and travel time for the examiner. Usually, the test itself will take between 2 and 4 hours, which includes a detailed pretest interview, collection of charts, an analysis of the polygraph charts, and a comprehensive written report.

You should also be aware that your test may come up as “inconclusive” for a variety of reasons. This doesn’t mean that you were lying, but it’s also not proof that you were telling the truth. In these cases, many people wish to get tested again, so you may want to find out how much your polygraph examiner will charge for retesting.

Be wary of someone who is charging significantly less than competitors. You may be getting a deal, or you may be getting someone who is not as qualified. The best way to ensure you are getting a trained professional is to ask for certification of their schooling and for proof of membership in a polygraph organization such as the American Polygraph Association or the National Polygraph Association. You should also take into consideration how many years of experience the examiner has.

Typically, I charge between $650 and $850, depending on travel time and the circumstances of the polygraph exam. To get a quote, you can contact me at (301) 791-7039 or contact me through this website.

Sources
Assured Polygraph Services, Inc.
Maryland Institute of Criminal Justice
Holland Polygraph Services