How it works
Almost nobody arrives knowing what to expect, and television has not helped. Here is the whole process, with no mystique attached to it.
The process
An appointment takes around two hours from arrival to leaving. Most of that is conversation, not testing.
1
Before you book, we talk through what you want the examination to establish. This is where we work out whether a polygraph can actually answer your question — and if it cannot, we will say so. A thorough pre-test is also carried out on the day to establish whether you can be tested at all.
2
You and the examiner write the questions together. Each one must be narrow, factual and answerable yes or no. You see and approve every question before anything is recorded.
3
Sensors record your breathing, cardiovascular activity and sweat-gland activity while the agreed questions are asked, several times, in a set order. Nothing is invasive and nothing hurts.
4
The examiner analyses the charts and explains the outcome to you before you leave. A detailed written report, including the questions asked and your answers, is emailed to the examinee within 24 hours.
On the day
You will be met privately and given time to settle before anything begins. Most of the appointment is conversation, not testing. People are usually surprised by how ordinary it feels.
Being nervous
This is the single most common worry, so it is worth answering directly. Being anxious about the situation affects the whole recording rather than particular questions, and the technique is built with that in mind. The long pre-test interview exists partly so that you are settled before anything is recorded.
If you become too distressed to continue, we stop. That is not a failed test.
Suitability
A valid examination needs an examinee who is fit to be tested. Please tell us about anything below when you book — it is far better to establish it beforehand than to travel to an appointment that cannot go ahead.
The examination is voluntary. The person being tested must give informed consent in writing and can stop at any point. We will not test anyone who has been pressured, threatened or misled into attending.
Eighteen is a hard limit. We do not test anyone under 18 under any circumstances, and there is no parental-consent route around it. Bring photo ID so we can confirm your age.
It is paramount that you tell the examiner about any medical condition, medication or mental-health issue before the test. Some conditions and some medications prevent a valid examination, and the examiner can only judge that if they know. Nothing you tell us goes any further.
Do not drink alcohol or take recreational drugs in the 24 hours before your appointment. Either will invalidate the examination, and you will have travelled for nothing.
We do not carry out examinations on women who are pregnant. This is a safety and validity decision, not a judgement, and it applies regardless of how far along the pregnancy is.
A thorough pre-test interview is carried out on the day to establish whether a valid examination can go ahead. If the examiner concludes it cannot, they will tell you and explain why.
Being straight with you
A polygraph does not detect lies directly. It records physiological responses, and a trained examiner interprets the pattern of those responses across carefully constructed questions. It is not infallible.
Polygraph results are not accepted as evidence in the criminal or family courts in England and Wales. If your situation involves a legal case, take advice from a solicitor before arranging a private test. Anyone who tells you a polygraph is 100% accurate or legally binding is overselling it.
A polygraph examination is a tool to detect possible deception. That is what it is for, and that is the limit of what it claims.
No pressure and no judgement. Ask a question first, or book a test when you are ready. Everything you tell us stays between us.