The relevant-control test is the type used for most employee screenings. Thus it is the most common type of examination. The interrogation consists only of irrelevant and relevant questions. As with the lie-control test, the first question and a few others are irrelevant. The relevant questions usually test workplace honesty: “Have you ever taken home office supplies for personal use?” Have you ever clock in for someone else?”

The premise is that no one will lie about everything. So if a few of the relevant questions produce heightened responses, they are presumed to be the questions on which the subject is lying. Unfortunately, there is no unambiguous way of deciding how much response indicates lie. Most psychologists agree that the relevant-control test is a poor test of deception.

The Reid/Inbau card trick is eliminated from employee screenings: There is too great of chance of coworkers comparing notes and discovering that everyone picked the ace of spades.

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