Distinguishing easily confusable categories requires learners to detect their predictive differences. Interleaved sequences — switching between categories — help learners to detect such differences. Nonetheless, learners prefer to block — switching within a category — to detect commonalities. Across two 2 × 2-factorial experiments, we investigated why learners scarcely engage in interleaving when learning confusable categories. In Experiment 1 (N = 190), we investigated the role of the utility value of being able to distinguish confusable mushroom doubles on their spontaneous study sequence choices and of the conditional knowledge component that for distinguishing, the detection of differences (between the doubles) matters. In Experiment 2 (N = 134), we again investigated the role of the latter and additionally of the conditional knowledge component that interleaving highlights differences. Results showed that combining two factors — increasing the utility value of distinguishing and informing learners that for distinguishing, the detection of differences matters — fostered learners’ use of interleaving. In conclusion, learners are more aware that interleaving highlights differences than previously thought. Nonetheless, learners prefer blocking because they do not recognize the utility value of distinguishing, and they lack the conditional knowledge that distinguishing requires finding predictive differences. Their blocked study sequence choices reflect a deliberate investment of effort to find commonalities rather than just avoiding effort. To make learners shift their effort allocation from finding commonalities to finding differences and engage them in spontaneous interleaving, we recommend highlighting the utility value of distinguishing and informing learners about the importance of finding differences for distinguishing.

区分容易混淆的类别需要学习者发现它们的预测差异。交错序列——在类别之间切换——帮助学习者发现这种差异。尽管如此，学习者更喜欢阻止——在一个类别内切换——来发现共性。通过两个 2 × 2 因子实验，我们调查了为什么学习者在学习易混淆的类别时很少进行交错。在实验 1（N = 190）中，我们研究了能够区分易混淆的蘑菇双打的效用值对其自发研究序列选择的作用，以及用于区分和检测差异（双打之间）的条件知识成分的作用很重要。在实验 2（N = 134）中，我们再次研究了后者的作用以及交错突出差异的条件知识成分的作用。结果表明，结合两个因素——提高区分的效用价值和告知学习者对于区分，发现差异很重要——促进了学习者对交错的使用。总之，学习者比以前想象的更清楚地认识到交错突出了差异。尽管如此，学习者更喜欢分块，因为他们不认识区分的效用价值，并且他们缺乏区分需要找到预测差异的条件知识。他们受阻的研究顺序选择反映了他们为了寻找共性而刻意投入的努力，而不是仅仅逃避努力。 为了让学习者将精力分配从寻找共性转向寻找差异，并让他们自发地交织，我们建议强调区分的效用价值，并告知学习者寻找差异对于区分的重要性。