Skill acquisition includes many issues, such as finding explanations for skillful performance, finding missing links in skill explanations, diagnosing performance malfunctions, identifying the role of “surprising facts” in skill discovery, and accommodating new skills. Interestingly, most of these issues are treated appropriately in an abductive reasoning framework. In this article, we focus on the skill of cello playing. A cellistmay find musical passages not playable using previously acquired methods alone. In such a case, we must invent a new skill, which we call an abduced skill. A simple case of skill abduction can be realized by adding a factual hypothesis, whereas in some cases we need rule abduction. In acquiring new skills, an instructor’s suggestion may improve a learner’s skill. This indicates the importance of such suggestions, which are called “surprising facts” in abduction. We point out the importance of surprising facts by showing two examples of dramatic improvement.

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