FAQ- Hogan Polygraph and Investigations

Frequently Asked Questions

It (i.e. polygraph otherwise known as lie detector) is the use of a scientific instrument known as the polygraph instrument to measure/ monitor the pulse rate, sweat gland activity, respiration, blood pressure and body movement of a subject or examinee by a competent polygraph examiner to detect the examinee’s truthfulness or deception with regards to a particular issue in an ongoing investigation.

Polygraph helps in finding out the truth about a situation or a particular incident in an ongoing investigation. It is a very useful tool in investigating and preventing fraud in an organization. Any person who requires the truth can make use of the polygraph. Any individual on medication needs to inform the polygraph examiner before the polygraph test begins. Polygraph can also be used in infidelity cases.

Based on extensive research and as published in the forensic science report journal, polygraph is about 95% accurate when conducted by a competent and certified polygraph examiner. Research shows that polygraph is more accurate than fingerprint, eye witness voice stress, etc. Aside from the competency of the examiner, other factors that can affect the outcome/ accuracy of the polygraph are: proper comprehension of the case facts, type of formats and scoring methods used, functionality of the instrument, condition of the testing room or location, psychological set on the part of the examinee and question formulation. 

The methodology of polygraph must be followed in order to ensure validity. Polygraph is divided into three phases: the pre-test, test and post-test phases. A qualified examiner will adhere strictly to the rules involved in each stage. So, an average polygraph examination will take a minimum of 90 minutes while it can extend to 3 hours depending on the examinee’s willingness to give details during the pre-test phase which should not be discouraged.

It is normal for anybody that wants to undergo polygraph examination to be nervous. General nervousness does not affect the outcome of the polygraph result.

Yes. The only party that can also have access to the polygraph result is the requester of the polygraph and the examinee will be duly informed about this in the early stage of the pre-test as this is very important.

Yes. All our examiners are fully trained and certified by accredited institutions either in the United States or South Africa. 

We have adequate testing rooms in our head office purposely prepared for polygraph examinations with the latest polygraph instrument, Lafayette LX600. We can also carry out polygraph examination in your office/ location anywhere, provided there is a SUITABLE space for polygraph examination.

The examinee should be well rested prior to the polygraph examination, no alcohol consumption 24 hours prior, should be in good health (the examiner must be informed in a situation of feeling unwell); also inform the examiner if you are on medication. No late arrival for the examination venue.