Abstract
The Matrix-method is being advocated as one strategy for promoting the application of the presented rule (p≡q) to problem-solving. This method intends to improve the reliance on the rule proposition and promote its application to the problem by reducing the validity of the anti-rule proposition (p・not-q, not-p・q) and making recognition of the close relation of the covariation between p and q by use of the logical matrix composed of four cells; p or not-p×q or not-q. The purpose of this study was to investigate one of the conditions that control the availability of the Matrix-method by the examination of its effect in situations where "pseudo-exceptions" (that is, phenomena or instances mistakenly regarded by learners as exceptions) come to the learner's mind. The results of an experiment indicated that the effect was reduced in the cases where the "pseudo-exceptions" come to mind as compared with the other cases. It was suggested, however, that its effect was maintained regardlees of the presence or absence of "pseudo-exceptions", provided the "pseudo-exceptions" were included in the Matrix-method as positive instances.