- Polygraph
- An instrument that measures and records physiological indicators — blood pressure, respiration, skin conductivity, and pulse — while a subject answers a series of questions, used to detect deception.
- Informed Consent
- A subject's knowing, voluntary, and uncoerced agreement to participate in an examination after being told its purpose, scope, and their rights.
- Employee Polygraph Protection Act (EPPA)
- A 1988 US federal law that prohibits most private employers from requiring, requesting, or using polygraph examinations on employees or applicants, with specific industry exemptions.
- Examiner
- A licensed or certified professional trained to administer polygraph examinations and interpret the recorded physiological data.
- Relevant Question
- A question directly related to the specific incident or matter under investigation, as opposed to a control or comparison question used to calibrate the instrument.
- Right to Withdraw
- The subject's ability to stop the examination at any point without penalty — a right that must be disclosed in the consent document in most jurisdictions.
- Countermeasure
- A deliberate technique — physical or mental — used by a subject in an attempt to distort polygraph readings and defeat detection.
- Polygraph Results Disclosure
- The circumstances under which examination results may be shared — typically limited to the requesting employer, law enforcement upon court order, or with the subject's written permission.
- Security Clearance
- Government authorization granting an individual access to classified information, often contingent on passing a polygraph examination as part of a background investigation.
- Specific Incident Investigation
- Under the EPPA, one of the narrow circumstances in which a private employer may request an employee polygraph — tied to an identifiable economic loss and reasonable suspicion focused on a specific individual.
- Voluntariness
- The legal standard requiring that consent be given freely, without duress, coercion, or misrepresentation — a condition courts examine when the admissibility of polygraph results is challenged.