Variation in inorganic chemistry instructors’ use of visualization tools in teaching molecular symmetry
Shanna Hilborn, Lu Shi, Samuel Pazicni, and Maia Popova
Molecular symmetry is a foundational yet challenging topic in the inorganic chemistry curriculum. Instructors draw on a range of visualization resources to support student learning of this topic, including pictorial representations, molecular model kits, and the Symmetry@Otterbein website. Yet, little is known about how and why instructors select, use, and coordinate these tools. To address this gap, we conducted semi-structured interviews, captured classroom observations, and collected course artifacts from fourteen inorganic chemistry instructors. Drawing on Magnusson’s Pedagogical Content Knowledge (PCK) framework, we elucidated instructors’ reasoning for using these visualization tools and examined how their thinking informs their symmetry teaching practices. We found that although instructors shared similar learning goals, consistently emphasizing visuospatial ability and representational competence, they selected and used visualization tools differently to achieve these goals. Analysis through Magnusson’s PCK framework showed that instructors’ reasoning most frequently reflected knowledge of students (KoS) and knowledge of instructional strategies (KoIS), with KoS often informing decisions about which visualization tools to use and how to use them. Practical considerations also shaped tool use, generally facilitating the use of pictorial representations and Symmetry@Otterbein while constraining the use of model kits. Finally, the visualization tools were frequently used in an instructor-centered way, limiting students’ interaction with them.
