A Method for Writing Open-Ended Curved Arrow Notation Questions for Multiple-Choice Exams and Electronic-Response Systems

A critical stage in the process of developing a conceptual understanding of organic chemistry is learning to use curved arrow notation. From this stems the ability to predict reaction products and mechanisms beyond the realm of memorization. Since evaluation (i.e., testing) is known to be a key driver of student learning, it follows that a new tool for evaluating student use of curved arrows could increase understanding of curved arrows. A robust assessment of this topic can be accomplished with open-ended mechanism questions; however, there are many instances where a multiple-choice format is desirable or required (e.g., exams in very large classes, standardized exams, or in-class "clicker" questions). Our evidence suggests that typical multiple-choice questions designed to assess curved arrow use are easy to answer even without a solid conceptual understanding of organic chemistry. This article describes a new assessment technique that allows instructors to ask open-ended questions about curved arrow notation in a multiple-choice format. We have found this innovation (and the one described in the accompanying article) to improve our ability to teach curved arrow notation and to assess student understanding of the concepts underlying this critical topic.