The truth about possibilities-based and truth-based truth table tasks
Kristien Dieussaert, Walter Schaeken, Walter Schroyens, Aline Sevenants · eScholarship (California Digital Library) · 2006
Truth table tasks are a popular way to investigate reasoning performance.In this paper, we make a direct comparison between the answer patterns yielded by two task formats used to investigate the mental representation of conditional sentences: the possibilities-based truth table task and the truthbased truth table task.In a truth table task, participants are asked to evaluate four logically possible cases produced by permuting the truth values of the antecedent and the consequent: true-true (TT), true-false (TF), false-true (FT) and false-false (FF).In the possibilities-based truth table task, they have to indicate whether a case is either possible or impossible according to the rule and in the truth-based truth table task, participants have to evaluate whether the case makes the given rule either true, false or is irrelevant with respect to the truth of the rule.Lately, a discussion of the status of "irrelevance" has emerged.The experiment shows that when participants have the opportunity to do so, they are inclined to judge the falseantecedent cases to be irrelevant rather than true with respect to the truth of a given rule.