Conjunctive Interpretations of Logical Connectives: Replication of Results Using a New Type of Task

Abstract

In an earlier study Damarin (1977) reported on the performance of subjects who were asked to judge the truth falsity of compound statements concerning membership of elements in pictured sets. More than 90% of these subjects-preservice elementary teachers-were found to treat both conditional and biconditional statements as conjunctions. Roughly half the population also treated the disjunction as a conjunction, whereas less than a third handled it correctly as inclusive or; only one subject treated the or exclusively. These findings contrast sharply with those of other researchers, who have found that similar subjects' performance on inference tasks can often be attributed to exclusive interpretations of or (Juraschek, Note 1) and treatment of conditional statements as if they were biconditional (O'Brien, Shapiro, & Reali, 1971). The tasks used by these researchers involve pairs of statements about familiar objects (e.g., dogs, balls, brothers) and ask subjects to indicate whether certain inferences can be drawn. The purpose of the present study was to examine subjects' interpretations of logical connectives when they appear in single statements concerning mathematical relations.