The mental model theory predicts variations in the percentage of errors in meta-propositional reasoning tasks but does not specify the nature of these errors (Johnson-Laird & Byrne, 1990). In the present
study, we drew predictions concerning the nature of errors in a meta-propositional reasoning task by importing and elaborating the distinction between implicit and explicit models previously applied by
the mental model theory to the domain of propositional reasoning (Johnson-Laird, Byrne, & Schaeken, 1992). An experiment was conducted in which participants were asked to solve problems concerning the
truth or falsity of propositional assertions. The task was to determine the truth-status (liar or truth-teller) of two persons making a propositional assertion about their own truth-status and/or the truth-status
of the other person. The results were consistent with the hypothesis that people may reason in ways that differ in the extent to which initially implicit models are made explicit. As such, the results corroborate
a basic principle of the mental model theory: the errors that reasoners make are consistent with at least one of the mental models they construct during the process of reasoning.