Instructional Decisions when Teaching Entropy: A Case Study on Topic-Specific Pedagogical Content Knowledge

Abstract

Physical chemistry is a mathematically intensive course that requires students to integrate mathematical and conceptual understanding of abstract topics, with previous research exploring instruction on thermodynamics, quantum mechanics, and general approaches to the course. However, there has been limited work on the impact of instructors’ pedagogical decisions related to student understanding of the topic of entropy. Within a larger research study exploring the cognitive resources activated by instructors when teaching entropy, the current case study aims to investigate how chemistry instructors’ values, goals, and lived experiences inform their pedagogical decisions when teaching the topic of entropy. Using the refined consensus model of pedagogical content knowledge as a guiding framework, semi-structured interviews were conducted with undergraduate chemistry instructors from multiple institutions. Participants were asked to define and explain entropy, represent the topic through focused content questions, and describe their instructional approaches. Findings revealed that instructors primarily relied on their knowledge of students and pedagogical knowledge to guide instructional decisions related to their content knowledge, with minimal emphasis on and integration of assessment and curricular knowledge with the remaining professional knowledge bases. These results highlight the need for further research into the development of interconnections between the five knowledge bases of topic-specific pedagogical content knowledge to better inform instructional practices in undergraduate physical chemistry.