1. What is a Polygraph?
The term "polygraph" literally means "many writings." The name refers to the manner in which selected physiological activities are simultaneously recorded. Polygraph examiners may use conventional instruments, sometimes referred to as analog instruments, or computerized polygraph instruments. Every polygraph instrument will collect physiological data from at least three systems in the human body.
At a minimum, convoluted rubber tubes that are placed over the examinee's chest and abdominal area will record respiratory activity. Two small metal plates attached to the fingers, or adhesive pads applied to the palmer surface of the hand, will record sweat gland activity. A blood pressure cuff, or similar device, will record cardiovascular activity. Additional pads or sensors may also be used.
A typical polygraph examination will include a period referred to as a pre-test, a chart collection phase and a test data analysis phase. In the pre-test, the polygraph examiner will complete required paperwork and talk with the examinee about the test. During this period, the examiner will discuss the questions to be asked and familiarize the examinee with the testing procedure. During the chart collection phase, the examiner will administer and collect a number of polygraph charts. Following this, the examiner will analyze the charts and render an opinion as to the truthfulness of the person taking the test. The examiner, when appropriate, will offer the examinee an opportunity to explain physiological responses in relation to one or more questions asked during the test.
2. Who uses the polygraph?
Polygraph examinations can be utilized by a wide variety of organizations or individuals. Some examples are as follows:
- Law enforcement agencies: criminal specific and pre-employment examinations
- Other agencies/organizations in the criminal justice system
- Attorneys involved in civil litigation
- Businesses/Organizations in the private sector (subject to EPPA)
- Private citizens in matters not involving the legal or criminal justice system.
3. What is the Employee Polygraph Protection Act (EPPA)?
See the comprehensive page on this subject by following the link on our main page.
4. Why do critics' figures vary?
One of the problems in discussing accuracy figures and the differences between the statistics quoted by proponents and opponents of the polygraph technique is the way that the figures are calculated. At the risk of over simplification, critics, who often don't understand polygraph testing, classify inconclusive test results as errors. In the real life setting an inconclusive result simply means that the examiner is unable to render a definite diagnosis. In such cases a second examination is usually conducted at a later date.
To illustrate how the inclusion of inconclusive test results can distort accuracy figures, consider the following example: If 10 polygraph examinations are administered and the examiner is correct in 7 decisions, wrong in 1 and has 2 inconclusive test results, we calculate the accuracy rate as 87.5% (8 definitive results, 7 of which were correct.) Critics of the polygraph technique would calculate the accuracy rate in this example as 70%, (10 examinations with 7 correct decisions.) Since those who use polygraph testing do not consider inconclusive test results as negative, and do not hold them against the examinee, to consider them as errors is clearly misleading and certainly skews the data.
5. Are there errors in a polygraph examination?
While the polygraph technique is highly accurate, it is not infallible and errors can and do occur. Polygraph errors may be caused by the examiner's failure to properly prepare the examinee for the examination, or by a misreading of the physiological data on the polygraph charts. Errors are usually referred to as either false positives or false negatives. A false positive result occurs when a truthful examinee is reported as being deceptive, while a false negative result occurs when a deceptive examinee is reported as truthful. Some research indicates that false negatives occur more frequently than false positives, while other research studies show the opposite conclusion. Since it is recognized that any error is damaging, and to ensure an unbiased review of the polygraph records, examiners utilize a variety of procedures to identify the presence of factors which may cause false responses. Some of these procedures may 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, as needed
If a polygraph examinee believes that an error has been made, there are several actions that may be taken, depending on the type and severity of error. Those actions may include:
- request a second examination
- retain an independent examiner for a second opinion
- file a complaint with a state licensing board
- file a complaint with the Department of Labor under EPPA
- file a request for the assistance of the American Polygraph Association
6. What is the scope of test questions?
Personal and intrusive questions have no place in a properly conducted polygraph examination. During pre-employment or periodic employment polygraph examinations, the examiner is generally prohibited from asking about: religious, racial, or political beliefs or opinions; lawful activities and affiliations regarding labor organizations; and sexual preferences or activities.
In a specific issue polygraph examination the relevant questions pertain to the particular act
under investigation. It should be understood that some of those topics listed above may be directly related to relevant issues when it comes to a specific issue test, and so may be open to reasonable examination and exploration.
7. Who gets the test results?
Polygraph results may be released only to authorized persons. Generally those individuals who can receive test results are the examinee, and anyone specifically designated in writing by the examinee, the person, firm, corporation or governmental agency which requested the examination, and others as may be required by due process of law.
8. What laws apply to polygraph examinations?
Currently, a majority of states have laws requiring licensure or certification for polygraph examiners. Most states require formal instruction, an internship training period and successful completion of a licensing examination.
Additionally, to date there are a significant number of states which have enacted legislation designed to regulate an employer's use of the polygraph. No state prohibits polygraph testing in all settings. This legislation is in addition to the Employee Polygraph Protection Act.
9. Is a polygraph admissible in court?
Polygraph results are admissible in some federal circuits and some states. More often, such evidence is admissible where the parties have agreed to their admissibility before the examination is given, under terms of a stipulation. Some jurisdictions have absolute bans on admissibility of polygraph results as evidence and even the suggestion that a polygraph examination is involved is sufficient to cause a retrial. The United States Supreme Court has yet to rule on the issue of admissibility, so the rules in federal circuits vary considerably.
10. How should I prepare for my scheduled examination?
Get a full night's sleep. Eat appropriately the day of the examination, and avoid excessive caffeine and nicotine. Do not consume alcohol or non-prescribed drugs, and use prescription drugs only in the prescribed dosage and at the appropriate times. Please be accurate with your examiner regarding prescriptions and dosages. Arrive for the examination on time or early, and be able to focus on the examination and issue at hand. Listen carefully to the instructions given by the examiner. Ask any questions you may have. Be prepared to answer questions calmly and truthfully, and resolve any issues during the pre-test phase that may otherwise result in deceptive responses. Do not withhold significant information in the hope it will remain undetected.
11. What does it mean when someone "fails" a polygraph examination?
Contrary to popular belief, there is no "passing" or "failing" grade to a polygraph examination. The examiner will determine whether or not significant physiological responses occurred to one or more of the relevant test questions. If significant responses did occur, it is a defensive physiological reaction in response to a question and the corresponding answer. Therefore, it is interpreted to mean deception of some sort is occurring. That deception may mean the examinee is lying. It also may mean the examinee is withholding critical or significant information regarding that question or topic. Follow-up actions to such a result vary widely, depending on the reason for the examination.
12. Can nerves or anxiety cause a "failed" test?
In a word, the answer is no. Virtually everyone submitting to a polygraph examination is nervous about something. It is natural and expected. A polygraph examination is a complex procedure, where the examiner is looking for a specific type of physiological response, a departure from the examinee's physiological baseline, to a specific question. A person can be very nervous, or very relaxed, and that will be their baseline for the duration of any particular testing sequence. Any one single question will not be negatively affected by general nervousness.
13. I've heard that people can "beat" the polygraph. Is that true?
It depends on your definition of "beating the polygraph". A polygraph instrument displays physiological data from your Autonomic Nervous System. Things like relative blood pressure and volume, and sweat gland activity, are quite difficult to control. There are a variety of ways in which certain responses may be manufactured or created by the examinee. However, this does not change the fact that significant physiological responses are still occurring to the relevant questions. What it does indicate is that the examinee is attempting to influence the test result. An astute examiner will spot these efforts with little difficulty, and will make a note of them. Whether there is a definitive examination result, or the examination must be considered Inconclusive, certainly such efforts go far in showing the examinee's mindset and intent. Such actions will likely not help the examinee be cleared from whatever suspicions are prompting the examination, and may very well result in a less favorable result than a truthful disclosure would.
14. Is there anyone you won't do a polygraph examination on?
If a person is pregnant, under twelve years of age, or suffering from certain significant medical or psychological issues, we will typically not conduct a polygraph examination.
15. Do certain medical conditions interfere with a polygraph?
Certain medical conditions and medications may have an effect on a polygraph. People suffering from delicate high blood pressure issues and significant stress-related medical concerns are strongly encouraged, and may be required, to receive a physician's approval prior to submitting to any polygraph examination. Certain medications may significantly interfere with a reliable examination result, and should be discussed with the examiner during the initial consultation. Additionally, people suffering from significant psychological or emotional problems may be considered on a case-by-case basis.
(A portion of the above information provided courtesy of the American Polygraph Association)
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