Some Empirical Justification of the Mental-Predicate-Logic Model

This chapter reports an initial test of the mental predicate logic developed in chapter 11. We examined (a) whether it can predict the relative difficulties of problems in a set of problems employing monadic predicates (i.e., predicates that take a single argument) and in a parallel set of problems employing dyadic predicates (i.e., predicates that take two arguments), and (b) whether erroneous evaluations of conclusions that are derivable on the direct-reasoning routine are relatively rare.