Three experiments examined content and context effects on the interpretation of if-then sentences as either conditionals or biconditionals. In Experiment 1, participants were from four grade levels, ranging from kindergarten to grade 12. All grade levels gave biconditional interpretations to sentences in which the antecedent was necessary to the consequent but gave conditional interpretations to sentences in which the antecedent was only sufficient to the consequent. In Experiment 2, subjects were from three grade levels, ranging from grade 4 to university. All grade levels interpreted the same abstract if-then sentences as conditionals in one context but as biconditionals in another context. However, university students gave more conditional interpretations than did the other participants when the abstract sentences were presented without context. In Experiment 3, university students\u27 interpretations of if-then sentences were correlated with their ratings of the necessity of the antecedent to the consequent. In addition, conditional and biconditional if-then sentences led to different equivalence judgments and paraphrases. Considered together, the results of the three experiments provided consistent evidence that content and context are crucial factors in the interpretation of if-then sentences. These findings are discussed in relation to (a) theories of if-then reasoning, (b) age differences in reasoning, and (c) the design of reasoning instruction programs
