Two Separate Questions
"Do I qualify?" is really two questions, and most people only think about the second.
The first question is about the case. Does the situation contain the raw material a Concealed Information Test needs? This has nothing to do with how serious the matter is or how sure anyone feels. It depends entirely on whether there are specific details that an involved person would know and an uninvolved person would not.
The second question is about the person. Is the individual who would wear the cap able and willing to take the test? This is the simpler of the two. Most adults can take a CIT without difficulty.
A case can fail the first question even when the person passes the second with ease, and that is the more common outcome. We turn away more enquiries because the details are not there than for any other reason. This page goes through both questions in order, so that you can judge your own situation before contacting us.
What the Case Needs
Three requirements. All three must hold for at least one detail, and ideally for two or three.
1. A specific detail exists
The test needs something concrete: a place, an object, a name, an amount, a date, a route, an item of clothing, a phrase. "Something happened at work" is not a detail. "The cash was taken from the second drawer of the grey filing cabinet" contains at least two.
The best details are the ones at the centre of the event, which an involved person could not have failed to notice. Research on the CIT has repeatedly found that central details, the things a person handled or did, are recognised more reliably than peripheral ones, the things that were merely present.
2. An involved person would know it
Ask yourself: if this person did what is suspected, would they certainly know this detail? If they could have been involved without ever learning it, a flat response proves nothing. A person who took money from a tin knows what the tin looked like. They may not know how much was in it if they never counted.
3. An uninvolved person would not know it
This is the requirement that most cases fail. The detail must not have reached the tested person by any innocent route. Consider each of these honestly:
- Have you said it to them, in conversation or in an argument?
- Have you written it in a text, email or letter they have seen?
- Has anyone else told them, such as a colleague, a friend or a family member?
- Was it in an official letter, a disciplinary notice or a solicitor's correspondence?
- Was it posted online or reported in the press?
- Have they been asked about it directly, even as a question? "Was it the grey cabinet?" discloses the grey cabinet.
- Would they know it anyway for ordinary reasons, for example because they work in that room every day?
If the answer to any of these is yes, that detail cannot be used. It may still be possible to find others that have stayed private.
Cases That Fit and Cases That Do Not
Worked examples make the requirements easier to apply.
| Situation | Fits a CIT? | Why |
|---|---|---|
| Money taken from a locked office. Only the manager knows which drawer, what it was kept in and how much. | Yes | Three central details, all withheld from staff. |
| A confidential document was leaked. Only two directors know the file name and which page was photographed. | Yes | Details are specific and tightly held. |
| A partner has found a first name and a hotel booking and has said nothing yet. | Yes | Two withheld details an involved person would know. |
| A partner suspects cheating but has found nothing specific. | No, for the standard test | There is no probe. A searching CIT may be discussed, with its limits. |
| An employee has received a letter setting out the full allegation. | No | Everything in the letter is now known to them innocently. |
| A couple have argued about the same named person for months. | No | The name is known to both. Recognition would mean nothing. |
| Someone wants to know whether a relative "is honest in general". | No | There is no event and no detail. |
| A person accused of damaging a car wants to show they do not know where or how it was damaged. | Yes, if the accuser has kept those details back | The accused volunteers; the withheld details are the probes. |
Notice that seriousness plays no part in this table. A minor matter with good details fits. A grave one with none does not.
How Many Details Do You Need?
One is the minimum. More is better, for a reason that is easy to see.
With one probe among six candidate items, there is always some chance that an uninvolved person responds most to the probe by accident, or because the word happens to mean something to them. With two independent details, an accidental response to both is much less likely. With three, less likely again. This is the main reason published guidance on the CIT recommends several items, and why the Japanese police, the largest field users of the method, routinely test multiple questions in one examination.
It works in the other direction too. A flat response to one detail might mean the person never noticed that detail. Flat responses to three central details are much harder to explain away.
In practice we aim for two to four blocks in an appointment. Beyond that, tiredness starts to affect the recording. If you have more candidate details than that, we choose the strongest together.
Who Can Be Tested
The requirements on the person are modest.
Consent
The person must agree, in writing, on the day, having had the procedure explained. Consent has to be real. We will not test someone who has been tricked into the room, who does not understand what the test is for, or who says they do not want to continue. They may stop at any point without giving a reason. We do not test anyone covertly, and the equipment could not be used that way in any case.
Age
We test adults aged 18 and over.
Reading and attention
The items are short written words or phrases in English. The person needs to be able to read them comfortably at a glance, with glasses or contact lenses if they normally wear them, and to keep attending for blocks of several minutes. If English is not their first language, tell us; items can often be chosen so that this does not matter, such as names, numbers or place names.
Sitting still
EEG is sensitive to movement. The person needs to be able to sit reasonably still, keep their eyes on a screen and keep their jaw relaxed for a few minutes at a time, with rests in between.
Hair and scalp
The sensors need to rest on the scalp. Most hair types are fine with a little gel. Very thick hair, tight braids, extensions, weaves or wigs over the midline of the head can prevent contact, and so can heavy hair products on the day. Please tell us in advance so we can advise. Hair should be clean and dry, with no oil, wax or spray.
On the day
The person should be rested, sober and not in a rush. A recording made at the end of a night shift, after alcohol, or in the middle of a heated argument is likely to be poor. We may postpone if the person is plainly not in a fit state to concentrate.
Things to Tell Us in Advance
None of these automatically rules a person out. They help us decide whether a usable recording is likely.
- A history of seizures or epilepsy. The test involves words appearing briefly on a screen at a slow rate, about one every two seconds. It is not a flashing-light stimulus, but we ask to be told and may advise checking with a doctor first.
- A neurological condition, a past head injury or brain surgery. These can change the EEG in ways that make the P300 hard to read.
- Medication that causes drowsiness or affects concentration. Sedatives and some other medicines reduce the P300. Nobody should stop prescribed medication for the test.
- Significant sight problems that are not corrected by glasses.
- Anything that makes sitting still difficult, such as a tremor or chronic pain.
- Implanted devices in or on the head. EEG is passive and does not interfere with them, but they can add electrical noise.
We are not medical practitioners and the test is not a medical examination. If there is any doubt about whether someone should take part, their own doctor is the right person to ask. Whatever the background, the target check described on the how CIT testing works page applies: if the person does not produce a clear response to the target, the block is reported as unusable and no conclusion is drawn.
Who Can Arrange a Test
The person booking and the person tested are often different people.
- Individuals arranging a test with a partner, relative or friend who has agreed to take part.
- People testing themselves, to show that particular details are unknown to them. In this case somebody else must hold the details: the other party, or a neutral third person, supplies the probes without telling the volunteer.
- Employers and business owners, where an employee has freely agreed. An employer should take its own advice on employment law before asking staff to take any test, and refusal must carry no penalty. We will not test anyone who indicates they feel compelled.
- Solicitors and investigators acting for a client, on the understanding that we make no claim about admissibility in any court or tribunal.
Whoever books, the tested person's consent is taken separately and directly by the examiner on the day.
Preparing the Person Who Will Be Tested
Good preparation is mostly about arriving in a fit state for a clean recording.
Nothing needs to be studied or rehearsed. The task is explained on the day and there is a short practice before the recording starts. What helps is ordinary:
- Sleep normally the night before. Tiredness reduces the brain response the test depends on and increases blinking.
- Wash hair that morning or the night before and leave out conditioner, oil, wax, gel and spray. Product on the scalp gets between the sensor and the skin.
- Eat beforehand. Hunger makes it harder to sit still and concentrate.
- Avoid alcohol for 24 hours and take prescribed medication as usual.
- Bring glasses if they are needed for reading a screen at arm's length.
- Leave time. A person watching the clock will not settle. Allow two hours so nobody is rushed.
- Arrange a quiet room if the test is at home: a table, a chair, a socket, and no television, pets or other people coming in and out.
The person arranging the test should not be in the room during the recording. Their presence is a distraction, and their reactions to the words on screen could give the probe away.
Common Misunderstandings About Qualifying
Assumptions we hear often, and what is actually the case.
"The more serious it is, the more suitable it is"
Seriousness has no bearing. Suitability depends on whether withheld details exist. A trivial matter with three clean details makes a better test than a grave one where everything has been said.
"I am certain, so the test will confirm it"
Certainty is not a detail. The test examines what the other person recognises, not how strongly you believe something. If you are certain because of specific things you found, those things may be usable. If you are certain because of a feeling, there is nothing to test.
"They will just deny it, so there is no point"
Denial does not matter to a CIT. The person is not asked to admit or deny anything. The measurement is taken from the brain response to the words, which appears whether or not they say anything.
"They are a calm person, so they will beat it"
The test does not measure calmness. A relaxed person is, if anything, easier to record cleanly. What can weaken the test is a deliberate trained technique, which is a different matter from temperament.
"They are a nervous person, so they will fail it"
Nervousness applies equally to every word on the list and therefore does not single out the probe. Extreme tension can make the recording noisy, in which case the block is reported as unusable instead of being scored.
"We can decide what to test on the day"
The item lists take care to build and are prepared and checked in advance. Turning up with no agreed details usually means no test can be run.
A Checklist Before You Book
Work through this in order. If you reach the end, your case is likely to be suitable.
- Write down what happened, as a short factual account. Leave out what you feel about it.
- List every specific detail in that account: places, objects, names, amounts, times, routes.
- Cross out anything the other person has been told, shown or asked about. Be strict. Include things said in anger.
- Cross out anything they would know innocently, because of where they live or work or who they know.
- Cross out anything an involved person might not have noticed.
- Count what is left. One is workable. Two or three is good.
- Check who else knows those remaining details and whether any of them could have passed them on.
- Confirm the other person is willing to take a test in which they watch words on a screen and press keys.
- Say nothing further about the details, and contact us.
If nothing is left after step five, the standard CIT cannot be built. It is better to know that now. We would sooner lose a booking than run a test whose result could not mean anything.
If Your Case Does Not Qualify
There are a few honest options.
Wait. If you expect to learn something specific soon, for instance from a statement, a record or a third party, a test can be built once you have it, provided you do not disclose it.
Consider a searching test. Where no true detail is known, a searching CIT presents candidate answers and looks for one that stands out. It is a real method used in field practice in Japan, but it is weaker than the standard test, it produces more inconclusive outcomes, and a clear result on it only tells you that nothing on the list stood out.
Use a different kind of help. A CIT cannot settle a general question of trust. For workplace matters, a properly run internal investigation may serve better. For relationship matters, a counsellor may be more use than any test. For anything that may become a legal matter, speak to a solicitor first.