Select Page

In Polygraph & Lie Detection & Lie Detector Testing, what is a Control Question?

polygraph lie detector examination

What is a polygraph, lie detection or lie detector control question?

In the course of a polygraph or lie detector test, a Comparison Question (sometimes referred to as “control question”) compares the examinees’ responses to questions they answer honestly to responses from questions they are instructed to lie to. For example:

Q: “Is today Thursday?” A: “Yes.” – truth
Q: “Is your name Abraham Lincoln?” A: “Yes.” – lie

This gives the polygraph examiner a baseline to compare responses to. Comparison question tests are widely applicable and are used both in specific-incident investigation and in screening. 1

Relevant vs. Irrelevant Polygraph Questions

A relevant question pertains directly to the situation. For example, if the case is about business theft, the polygraph (lie detection) examiner may ask, “Have you ever embezzled?”

An irrelevant question is one designed to provoke no emotion (e.g., “Is water wet?).

The relevant-irrelevant test format was the first widely used polygraph testing format and was long the dominant format. The format was originally used in criminal testing. Currently, it is also used in multiple-issue screening applications, for example, at the U.S. National Security Agency.


The Polygraph Examiner provides professional polygraph and lie detection tests for infidelity, cheating, or relationship struggles, as well as business theft, criminal cases, pre-employment, sexual assault accusations, sex offender cases, and sports integrity. Call our offices today for a FREE phone consultation at 800-497-9305.

Call The Polygraph Examiner Now

Call us at anytime at (800) 497-9305 to discuss polygraph & lie detection testing for your any reason. Call The Polygraph Examiner for information about LOCAL polygraph & lie detection tests in North Carolina, South Carolina & Georgia at (800) 497-9305.

  1. See also “Appendix A: Polygraph Questioning and Techniques.” National Research Council. 2003. The Polygraph and Lie Detection. Washington, DC: The National Academies Press. doi: 10.17226/10420.
Click to Call 800-497-9305