Most polygraph examiners, especially those who are members of professional associations, know that there is no future in unethical behaviour and will not jeopardise their careers by providing false results to suit a specific person.

The professional polygraph examiner will allow other polygraph professionals access to the recorded data to render second opinions.

It provides a certain assurance that no manipulation of the results happened.

The computer is used to record the physiological responses displayed by a subject during the examination.

Bespoke software, developed by the manufacturers of the equipment, governs the process.

This software does not allow the recorded data to be altered or manipulated in any way by the polygraph examiner.

The software prohibits the polygraph examiner to access the recorded data at all.

The pure recorded data is the only information that can be used by an examiner to substantiate his opinion.

The polygraph result constitutes the opinion of the polygraph examiner based on the procedure that he or she has performed. (Similar to the diagnosis of a doctor based on his examination.)

The opinion does not necessarily constitute proof. Proof, as required by a court of law, has to satisfy certain criteria.

A mere opinion does not meet these criteria. The polygraph result was never intended to provide proof.

The adage applies: To know is not to prove! It provides a very solid indication to assist with the continued investigation.

Unless the examinee is so nervous that he or she cannot sit still, nervousness does not affect the polygraph result.

As a matter of fact, all polygraph subjects are expected to be nervous.

As the ‘resting’ levels of the person are not known, the prevailing levels of nervous tension present the baseline and only responses deviating from this baseline are considered.

Don’t trust websites or persons offering “relevant” advice. Your efforts to try and manipulate a polygraph examination is likely to be noticed by the examiner (who is highly trained and experienced). Not only will you look stupid, but concerns will surface as to why you are trying to manipulate the outcome.

•request a second examination

•retain an independent examiner for a second opinion