In this work we present the application of design based research (DBR) methodology to conduct a systematic iterative study of the design and implementation of a teaching-learning sequence (TLS) on emf (electromotive force). This work is the final part of a broader study that started with the analysis of students’ difficulties with emf in the contexts of transitory current, direct current, and electromagnetic induction. We complete our research by investigating to what extent students see emf as a cross-cutting concept. We establish the design parameters based on an epistemological analysis and the empirical data, and describe how we devised and implemented the first version of the TLS that takes 4.5 h of classroom time. We analyze the data obtained in the first implementation and describe the redesign process that resulted in a second version of the TLS that takes 1.5 h of classroom time. We conclude that both versions of the TLS effect a similar boost in student attainment of learning objectives compared to the control group.

中文翻译：

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通过教学序列引导学生理解电磁现象中的电动势概念

在这项工作中，我们介绍了基于设计的研究（DBR）方法的应用，以对电动势（emf）上的教学序列（TLS）的设计和实现进行系统的迭代研究。这项工作是更广泛研究的最后一部分，该研究从分析瞬态电流，直流电和电磁感应情况下学生的电动势困难开始。通过调查学生在多大程度上将电动势作为一个贯穿各领域的概念，我们完成了研究。我们基于认识论分析和经验数据建立设计参数，并描述我们如何设计和实现需要4.5小时课堂学习时间的TLS的第一个版本。我们分析了在第一个实现中获得的数据，并描述了重新设计过程，该过程导致TLS的第二个版本花费了1.5小时的课堂时间。我们得出结论，与对照组相比，两种版本的TLS对学生学习目标的实现都有类似的促进作用。