本研究では,提示したルール(p≡q)が課題解決に容易に適用されない理由の一つに,「判断の不確定性」(ルール不支持方向の命題[p→非q,非p→q]にも一定の妥当性を付与して判断の依拠する命題を一つに確定しないこと)を挙げ,これを低減する方略の有効性について検討した。その方略とは,p・非p×q・非qの4つのセルからなる論理操作マトリックスを用いてルール命題の妥当性の検証過程を示す方法(マトリックス検証方略)であった。経済的競争ルールを取り上げた実験Iでは,「判断の不確定性」の存在が確認され,併せてマトリックス検証方略が,従来の事例提示方略の効果を上回って課題へのルール適用を促進することが示された。植物生殖ルールを取り上げた実験IIでも,同様の結果が得られた。これらの結果から,マトリックス検証方略の有効性とその限界について,また事例提示方略との関係性について,そしてこの方略の授業場面への利用可能性について考察を加えた。

Uncertainty of judgment is defined as the uncertainty of choosing a proposition as grounds for a judgment in rule learning because of giving a certain amount of validity to the anti-rule proposition [p → not-q, not-p → q] in the same way as the rule proposition [p≡q]. The purposes of the present study were to identify this uncertainty as a major reason why it is difficult to apply a rule to problem-solving, and to investigate an effective method for reducing uncertainty. The participants (university students) were shown the process of inspecting the validity of a rule proposition using a logical operation matrix composed of 4 cells : p・not-p × q・not-q (matrix inspection method). In Experiment 1, using an economic competition rule, the uncertainty of judgment was verified, and the matrix inspection method was found to promote the application of a rule more than the usual method of presenting examples did. Experiment 2, which used a plant reproduction rule, had similar results. The effectiveness and limits of the matrix inspection method, the relationship of that method to the method of presenting examples, and the availability of that method for classroom teaching were discussed.