The literal meaning of “polygraph” originated from the Greek word “polygraphos”. Poly: meaning many or much and graphos/graph meaning writing or recording.

According to the dictionary, the polygraph is a measuring device, which makes a permanent recording to various physiological changes taking place within the body of the test subject; as a result of certain psychological stimuli. These stimuli are brought about by asking questions, structured and phrased in a specific way, and by maintaining a certain environmental and emotional climate during the examination.

During the pretest interview, the polygraph examiner will explain your legal rights, explain the polygraph instrument and how it works, discuss the issue, develop and review all questions asked on the polygraph test, cover general background information, and will provide instructions for the actual testing phase.

It is expected that anyone who takes a polygraph test will be nervous; however nervousness does not normally interfere with the test. Even though a person has high blood pressure, diabetes etc., their body has a set of normal patterns. When a person decides to lie, however, physiological changes take place in the body. Blood pressure may begin to elevate. Heart rate can increase or decrease. A person’s heart can skip a beat. Blood volume begins to change. A person’s respiration (breathing) and perspiration (sweating) may show marked changes. These are just a few of the types of physical changes that can occur.

A professional polygraph examination has three phases: a pretest phase, a data (chart) collection phase, and a post-test phase, which includes test data analysis. A typical polygraph examination will last at least two hours, and sometimes longer.

Polygraph Testing – In the pretest phase, required paperwork is completed and the polygraph examiner gets to talk with the examinee about polygraph and the issue being tested.

The “chart collection” phase takes place in a quiet room where distractions are held to an absolute minimum. The examiner will attach the sensor components to the person and then ask the previously reviewed questions that are designed to be answered “yes” or “no”. Data is collected by the sensors and instrument and a computerized recording of physiological responses is obtained.

In the Post test phase, the examiner will analyze and score the chart data and render an opinion as to the truthfulness of the person being examined. Polygraph Tests – Scottsdale, Arizona.

The polygraph has been in use for over 75 years. During that time approximately 250 studies have been conducted on the accuracy of polygraph tests. Since conditions and factors involved in research will vary, and since a polygraph examination is a very complex process, it is difficult to extract a precise accuracy figure from the data. Nevertheless, the preponderance of available information indicates that the accuracy of a properly trained examiner, utilizing established testing procedures, is around 95% for specific-issue investigations.

While the polygraph technique is not infallible, research clearly indicates that when administered by a competent examiner the polygraph test is the most accurate means available to determine truth and deception. Since 1980, a compendium of research studies – encompassing 80 research projects involving 6,380 polygraph examinations and 12 studies of the validity of field examinations following 2,174 field examinations, indicate an average accuracy rate of 98%.

Contrary to popular belief, polygraph results are admissible in most courts across the country. The Supreme Court has yet to rule on the issue of polygraph admissibility so it has been up to individual jurisdictions to allow or disallow them. There are some jurisdictions that have bans on admitting polygraph results, but most allow them if both the plaintiff and the defendant have agreed (stipulated) that the results of the test will be admissible prior to the examination being conducted. For more details on admissibility and case citations for each state, visit

Yes. We at Precise Polygraph hold ourselves to very strict confidentiality and privacy standards. All information from an examination is kept strictly confidential and private except for PCSOT examinations where the results are reported to the Treatment Provider and the Supervising Official. Are There Errors In Polygraph Examinations? (The False Positive & the False Negative) While the polygraph technique is highly accurate, errors can occur. Errors are usually referred to as either false positives or false negatives. A false positive occurs when a truthful examinee is reported as being deceptive. A false negative occurs when a deceptive examinee is reported as truthful. Since it is recognized that any error is damaging, examiners utilize a variety of procedures to identify the presence of factors which may cause false responses, and to insure an unbiased review of the polygraph charts.

These 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.
  • Utilizing only validated testing formats and protocol.
  • Factual analysis of the case information.  A thorough pretest interview and a detailed review of the questions.
  • Quality control reviews.

(Inconclusive or No Opinion)

An inconclusive or no opinion result simply means that insufficient data is available for the examiner to render a definitive opinion of deception indicated (DI) or no deception indicated (NDI). In such cases a second examination is usually conducted in an effort to arrive at a decision. The classification of a polygraph examination as “inconclusive” protects the examinee from being falsely identified as deceptive when inadequate data is collected. Critics of polygraph have wrongly classified inconclusive test results as errors. In actuality, a determination of inclusive is made to avoid errors in identifying truthfulness or deception of an examinee.

Professional polygraph examiners take specific steps to mitigate circumstances that may affect the results of the exam. They also take outside factors into consideration when administering the test and analyzing the data to eliminate factors not related to the examination.

No. While a person’s heart beat and respiration rate may increase when he or she is nervous, a qualified examiner understands this and will take it into consideration when evaluating an examinee’s response. Unlike general nervous tension, an examinee’s deceptive responses is highly specific. An examiner mitigates a nervous response by reviewing the questions with the examinee and through an acquaintance or “practice test” prior to the exam. Source: American Polygraph Association.

Fees vary depending on the type of exam and location where it is administered. . A deposit, or credit card, is required to calendar an appointment. Remember that the Psychophysiological Detection of Deception via the polygraph is a technical skill requiring extensive training and specialized digital instrumentation.

As an employer, can I have prospective employees screened with the polygraph . . . . . or current employees tested?

Employee polygraph testing is regulated by the Employee Polygraph Protection Act (EPPA 1988) and is allowed under only certain circumstances. Pre-employment testing (screening) is prohibited by private employers, and testing of current employees can be complex, expensive, and expose employers to potential liability if improperly conducted. Employers should always consult with an attorney before scheduling a polygraph exam for any employee.

Examinations require an appointment but Precise Polygraph will try to accommodate a same day appointment with enough time.

Appointments are scheduled on our website or over the phone Monday through Friday, from 8:00 AM to 5:00 PM, and some weekends. Weekend appointments are upon request.

  • Get a good night’s sleep and eat something before the examination. Do not schedule your test at the end of a long, hard workday; you want to be fully rested for the examination. If possible, schedule the test on your day off, or at the beginning of your day.
  • Do not consume any alcoholic beverages or illegally use any drugs for 24 hours prior to the examination.
  • If you are taking a prescribed medication, continue to take the medication according to your doctor’s instructions. If you are worried about the effect of any drug on your ability to take the examination, call before the test and discuss the matter with an examiner.
  • If you have any injury, illness, or physical condition that you feel could affect your ability to take a test, call and discuss the matter with an examiner.

Dress comfortably for private polygraph examinations, but please do not wear: tank tops, gym shorts, sweats, bathing suits, baggy shirts, bulky sweaters, or soiled clothes. All polygraph sensors will be donned on the outside of the clothes you wear. If you are taking an exam for pre-employment or other professional purposes, a suit and tie are not required; ‘business casual’ attire is recommended for those situations.

In most cases you will receive the results the day of the exam, and occasionally on the following day. At the conclusion of a private exam, you may request to receive a written report detailing the examination and results. Your examination and the results are considered confidential, and will not be discussed with, or disseminated to, any third party without your consent in writing.

Be Open and Honest with your Background Investigator as well as your Examiner. And Always Tell the Truth!

No. In many States LICENSING is not required. That means anyone can read a book on Polygraph, buy an instrument and call themselves an Examiner. There are no controls in those States as to who provides such services, Consumer Beware. We at Precise Polygraph are Certified Polygraphists in the State of Arizona and will always provide the best services to our Clients. 

We provide our clients with the most scientifically validated techniques and technologies available, with the most up-to-date computerized instrumentation available; following standards set by the American Polygraph Association.


How is the Polygraph Examination performed?

The polygraph exam is performed on a Computerized Polygraph System (CPS), both acknowledged and certified by The American Polygraph Association.

If you have other questions, please do not hesitate to contact us.