Chapter 8: How Do Students Reason When They Have to Describe the “What” and “Why” of a Given Reaction Mechanism?¹

Students' mechanistic reasoning has been the focus of research in recent years. To initiate and research this reasoning, students were asked to explain mechanistic steps for mechanisms in organic chemistry formerly unknown to them. The mechanisms were divided into their singular steps and captions for each mechanistic step were written by the students resulting in mechanism comics. These mechanism comics were qualitatively evaluated. The coding process included three rounds. The written captions were assigned as ‘descriptive’ or ‘causal’, were assigned as ‘activities’ or ‘properties of entities’ and in the last round were analyzed to decide whether they were ‘technically correct’, ‘partially correct’ or ‘not correct’. The analysis shows that the students' reasoning was mostly descriptive. They described ‘what’ happened in the mechanistic steps with less ‘why’. The students mostly described ‘how’ the particles interacted. Because the mechanism comics do not need much time and effort, they are a suitable instrument for learning the design of reaction mechanisms and for getting insights in the quality of students' mechanistic reasoning.