How accurate is a polygraph?

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U.S. Government studies have concluded that when a qualified examiner conducts the test properly, the polygraph exam is between 88 and 91 percent accurate.

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What type of questions can be asked?​

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Test questions must be limited to “yes” or “no” and "true" or false" answers. The test questions must have definite objective answers and may not be opinions. The test questions must relate to past events of a factual nature.

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How many questions can be asked?​

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An examiner can usually cover three (3) relevant questions during an exam. This assumes these questions are related to one another (see the question above). It takes about 60 minutes to cover these three questions effectively. If it is necessary to ask more questions, another exam must be designed and conducted. This will add to the time and cost involved. Test results are usually less reliable with an increase in the number of relevant test questions. A healthy individual can only produce readable polygraph charts for a limited period of time; after this time has passed it is impossible to generate a conclusive polygraph test.

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What should I look for when hiring a polygraph examiner?​

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The rapport between the examiner and examinee is paramount in conducting an effective polygraph examination. There some polygraph examiners who will offer very low rates, unlimited questions, they are known to talk down and are very argumentative with examinees. Some polygraph examiners in Arizona will even give results based on the highest bidder. If your looking for an unethical examiner, we are NOT that company.

 

Our examiners strive to keep a good rapport with examinees. All of our test results are not based on our examiners opinion, but based off the computerized polygraph results.​

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What does the test consist of?​

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The polygraph examiner receives and reviews the facts of the case. The examiner formulates the specific test questions based upon the facts of the situations and the examinee’s version of the events.

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The examiner explains the test process to the examinee and reviews the facts of the case during the pretest interview. At this time the examiner reads each question to the examinee to make sure each one is easily understood.

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The examinee is attached to the polygraph instrument and given additional instructions. 

 

The questions are read by the examinee while they are attached to the polygraph instrument using sensors that measure eyes, heart rate, breathing, seat pad and sweat gland activity. These measurements are charted on graphs or stored in the memory of computerized polygraph units.

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Upon completion of the questions, the computer will analyze the charts and numerically score the charts to make sure that his analysis is within the acceptable limits of the instrument. This score results in a conclusion that the examinee has answered either truth, deception or is determined to be inconclusive.

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The examiner will transmit the test results to the client verbally as soon as is practical. A written report will be provided if requested.

 

NOTE: Polygraph exams are conducted in private. No other persons are allowed in the examination room during the test. Most reputable examiners videotape the examination for the protection of all parties involved.