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The Verifiability Approach (VA)

The verifiability approach, conceptualized and developed by Galit Nahari, is a strategy-based method for lie detection.

Using the liars’ strategy to uncover their lies

Liars tend to provide details that their truthfulness cannot be checked. Exploiting this strategy, by using verifiable details as indicator, increase the ability to detect lies.

The liars’ dilemma hypothesis

When providing an account, two contradicting motivations put Liars in a dilemma. On the one hand, they are motivated to report many details to make an honest impression, and on the other hand they are motivated to avoid providing details to minimize the chances of being caught. A strategy that compromises between these two conflicting motivations is to provide details that cannot be verified. Consequently, liars tend to report fewer verifiable details than truth tellers, and this tendency can be used to detect their lies.

Resistance to countermeasures

Liars may obtain insight into the working of the tool and will attempt to influence their own responses so that they will be judged as truth tellers. Such attempts are termed countermeasures. The verifiability approach is resistant to countermeasures.

The countermeasures resistance hypothesis

Liars are unable to counteract the verifiability approach, simply because they do not have truthful verifiable details to provide. Fabricating verifiable details is not an option too, as it may lead to the refuting of their accounts.

Increasing the verifiability Approach effectiveness

by using Information Protocol

Knowledge about the working of the Verifiability Approach actually facilitate rather than hamper lie detection.

The facilitating effect of information protocol hypothesis


Encouraging interviewees just before they provide their statements to include many verifiable details increases the effectivity of the Verifiability Approach in detecting lies, because only truth tellers can face this challenge.

What are Verifiable Details? 

  1. Activities that were carried out with named persons or persons who can be identified based on the description given. 

  2. Activities that were witnessed by named persons or persons who can be identified based on the description given.

  3. Activities that were documented, recorded or that the interviewee believes may have been captured on CCTV. 

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