ABSTRACT
Given that the competing mental-logic and mental-model accounts of propositional reasoning have led to a prolific exchange of arguments and counterarguments, as well as analyses and reanalyses of foundational work, one would assume that a neutral observer would have enough data to determine which theory better describes such reasoning. This is not the case, however. The debate’s empirical findings vary sufficiently to run the risk of leaving the neutral observer nonplused as to which position is more supportable. For example, consider the contradictory reports concerning responses to the disjunctive premise set presented in (1):
Whereas Johnson-Laird, Byrne, and Schaeken (1992) reported relatively low rates (30%) of correct responses to (1), the mental logic approach typically has reported high rates (often above 90%), as to be expected for a mental-logic schema (chaps. 7 and 8; see also Braine & Rumain, 1981). How does one reconcile such wildly divergent findings concerning a fundamental inference? This chapter endeavors to address the contradic-tory findings, not only to maintain the integrity of the empirical literature, but also to help resolve part of a wider debate between the mental-logic and mental-model theories.
