What is a polygraph?
A polygraph is an instrument that records various physiological changes in the body of the examinee while being asked specific questions. Those questions can cause an examinee to have a psychological response which causes the examinee’s body to react, which causes a physiological response. Physiological responses in respiratory, electro-dermal and cardiovascular activity are recorded.
How much does a polygraph exam cost?
Cost will vary depending on the complexity of the case. More complex cases require a significant amount of time which increases the cost. Beware that all polygraph examinations are not equal and any examiner offering to complete examination for a significantly reduced price should be throughly vetted, equipment used, software updates, completion of schooling through an American Polygraph Association approved school, membership to at least one professional organizations and completion of on-going training. If the issue is important enough to get a polygraph, it’s important enough to get a good quality examiner.
How do I select a quality polygraph examiner?
California does not require a license to conduct polygraph examinations, so it’s important to educated yourself as a consumer. Here are just a few questions to consider asking. Has the examiner attended a accredited Polygraph school? Do they belong to any professional associations? Are they bonded and insured? Are they attending ongoing professional education? This is just a few questions you should be asking.
What happens during a polygraph examination?
Prior to the examination, we will review all the important information (case, facts) related to the needs of the exam. Once you arrive for the polygraph exam, there are generally three phases that will occur. Pre-examination, Examination and Post-examination. In the Pre-examination phase, we will complete all the necessary paperwork and review the case with you. We will explain the how the examination will be conducted and review all questions with you at that time. In the Examination phase, we will attach the polygraph sensors to you. We will then ask all the previously reviewed questions. Most questions are answered with a “yes” or a “no” response. The physiological changes in your body will be recorded on a chart. In the Post-examination phase, we will analyze the charts, using a numerical scoring system. The numerical scoring system will allow us to make one of three determinations, truthful, inconclusive or deceptive. When appropriate the examinee will be given the opportunity to explain any physiological responses to one or more of the questions. The results will be given to the client as soon as practical, with a written report to follow.
How does a polygraph work?
Respiratory activity is recorded by placing two expandable sensor tubes on the examinee. One tube is placed on the examinee’s chest above the heart the second is place around the abdomen. Galvanic Skin Response, or sweat gland activity is recorded by attaching two small metal plates to two of the fingers. Cardiovascular changes are recorded by using a blood pressure cuff. All those micro changes are recorded while the examinee is asked a series of questions. An examinee’s responses to questions are given a numerical score using criteria standard for the polygraph technique that is being used.
How long does a polygraph examination take?
American Polygraph Association standards require that the polygraph examination process to be 90 minutes at a minimum. The examination can take longer depending on number of considerations, such as the complexity of the case or questions posed by the examinee. Generally a polygraph examination will take approximately 3 hours.
What questions will be asked during the examination?
That depends upon the case. We will review all the questions with the examinee prior to the examination. There are no surprise questions.
How accurate is a polygraph?
From the American Polygraph Association website: The American Polygraph Association (APA) believes that scientific evidence supports the validity of polygraph examinations that are conducted and interpreted in compliance with documented and validated procedure. Thus, such examinations have great probative value and utility for a range of uses, including criminal investigations, offender management, and selection of applicants for positions requiring public trust. The APA Standards of Practice set some of the highest professional requirements for its members to ensure their polygraph services are valuable, reliable, and promote ethically responsible practices. The APA also produces a variety of model policies that represent the current understanding of best practices, and makes them widely available so that polygraph examiners (both APA members and non-members) and their clients can be aware of what constitutes a valid examination process. The APA believes that well informed departments, agencies, and clients will insist on APA members for their polygraph services. Recently the APA undertook an exhaustive review of all of the peer-reviewed publications on polygraph testing that represented field practices and which met the requirements of the APA Standards of Practice. A meta-analysis was conducted, and a report was completed in late 2011. An executive summary of the report is freely available to the public through this website. Please visit the Executive Summary of the Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques page to download the summary and FAQ section. The executive summary reports that 38 studies satisfied the qualitative and quantitative requirements for inclusion in the meta-analysis. These studies involved 32 different samples, and described the results of 45 different experiments and surveys. They included 295 scorers who provided 11,737 scored results of 3,723 examinations, including 6,109 scores of 2,015 confirmed deceptive examinations, 5,628 scores of 1,708 confirmed truthful exams. Some of the cases were scored by multiple scorers and using multiple scoring methods. The data showed that techniques intended for event-specific (single issue) diagnostic testing produced an aggregated decision accuracy of 89% (confidence interval of 83% – 95%), with an estimated inconclusive rate of 11%. Polygraph techniques in which multiple issues were encompassed by the relevant questions produced an aggregated decision accuracy of 85% (confidence interval 77% – 93%) with an inconclusive rate of 13%. The combination of all validated PDD techniques, excluding outlier results, produced a decision accuracy of 87% (confidence interval 80% – 94%) with an inconclusive rate of 13%. These findings were consistent with those of the National Research Council’s (2003) conclusions regarding polygraph accuracy, and provide additional support for the validity of polygraph testing when conducted in accordance with APA Standards of Practice.
What types of polygraph examination are there?
There are generally two main type of polygraph examinations that are used, but a number of others exist for specific circumstances. First is a Multiple issue examination, which allow for a larger scope of questions but are considered less accurate. The other is a Specific issue examination, which are considered the most accurate, but are limited in scope to one specific issue.
Will being nervous affect the results?
It is expected that all examinees will feel a level of nervousness. That is completely normal. Being nervous will not cause deceptive results.
Will the medication(s) that are prescribed by my doctor, affect the results of my examination?
Examinees should continue to take medications as prescribed by your doctor. Some medications can affect the physiological response in your body. Please notify me of your current medications so that a suitability for examination assessment can be made. IMPORTANT NOTE: Do not take any illegal drugs or alcohol before the examination
Are polygraph examination admissible in court?
Polygraph admissibility varies. Results of the polygraph examination are most often admissible when both parties have agreed (or stipulated) to allow the results of the polygraph examinations, prior to the examination being conducted.