A polygraph test usually takes about 2 hours or less and consists of a pre-test screening interview which lasts anywhere from 40 to 90 minutes, procedure of collecting answers for the questions asked, and the analysis of the answers received. The duration of the second and third stages depends on the issues at play.

The person administering the test is a qualified polygraph examiner who can be a private investigator or a professional whose job is to provide polygraph test services. Private investigators are usually employed when the person in question answers polygraph test questions for employment purposes.


If the subject is required to take a polygraph test, his or her full consent must be obtained. This is especially important in a business situation such as incident investigation within a commercial organization or a new staff member vetting process. Taking a polygraph test during a hiring process has to be consensual and perceived by both the subject and the organisation as important and in the interest of both parties.


Main Prerequisites

The main prerequisites for a customer taking a lie detector polygraph test are that he or she must not be under the influence of any drugs or alcohol during the lie detector test, because it might affect the body’s responses to questions and make the results inconclusive and perhaps even false.


Dress Code For Taking A Polygraph Test

There is no real specific dress code for taking a polygraph test. However, if the test is taken for employment purposes, it is recommended that the subject wears something like a suit – a polygraph in that situation is just another part of a job interview. The important thing, however, is for the subject to be comfortable when answering the questions in the lie detector test; therefore business casual attire would be appropriate. If the subject of pre-employment screening is taking a police polygraph test or a firefighting polygraph test, he or she should inquire about the appropriate procedure attire in advance.


Answers To The Questions

During the second stage of the test, the subject gives answers to previously agreed polygraph questions, and the machine detects whether he or she is telling the truth by reading and evaluating their body’s responses. The answers given can either be “Yes” or “No”. The answers to the questions must be pivotal to solving the issue at hand, and the questions asked during the lie detector test must therefore be relevant and direct. The examiner should not ask trick questions that have not been agreed between them and the subject because the subject must have consented to answer all the questions.


Analyze The Results

After the test is completed, the examiner will analyze the results and make a decision as to whether the subject is truthful. The training for the occupation of a polygraph examiner includes learning how to interpret the polygraph results. They are also trained to differentiate nervous reactions displayed on polygraph charts from the reactions that occur when the subject is lying deliberately.