二重課題が誤検索効果に及ぼす影響

Tests in educational situations are mainly used to measure how much of the learners’ knowledge and skills have become fixed. However, participating in a test in itself enhances learning. The effect of enhancing learning, especially by making mistakes in tests, is called the “failed retrieval” effect. A variety of studies have explored this effect. For example, many previous studies have shown that learning facilitation will not occur when there is a delay in correct feedback after retrieval of the test. However, other studies have repeatedly shown that learning facilitation occurs even after delayed feedback. In addition, these studies suggested the possibility that learning facilitation was not caused by delayed feedback because the learners’ attention was divided when retrieving misinformation. In this study, we therefore conducted a dual-task in parallel with the initial test where the learner retrieves misinformation to examine the effect of divided attention on the failed retrieval effect. Half of the learners were assigned to a divided-attention group, which performed a digit-classification task simultaneously to the initial test. As a result, the divided attention during misinformation retrieval inhibited learning facilitation. This effect was particularly large when feedback was delayed. Therefore, this study suggested that divided attention was the reason why the failed retrieval effect did not occur if the feedback was delayed in the previous study. Thus, the delayed feedback possibly could promote learning without divided attention.