| Abstract: | A total of 224 subjects in grades 2, 4, 6, 8, high school, and college solved problems requiring comprehension of the logical connectives and, or, if-then, only if, and if and only if, as well as the terms is and is not. Half the subjects were required merely to encode the connectives; the other half were required to combine as well as encode them. Problems were presented in two replications (over two sessions) via two different content vehicles. Quantitative analyses revealed significant effects of task, age, session, and connective, with comprehension of different connectives developing at different rates. In general, comprehension of the conjunctive connective was easiest; comprehension of the conditional and biconditional connectives was most difficult. Qualitative analyses indicated just how the logical connectives were interpreted at each grade level, and also investigated individual differences within each grade level. |
