P152: Developing a learning progression on chemical synthesis
In order to support the development of learning progressions about central ideas and practices in chemistry, we need detailed analyses of the implicit assumptions and reasoning strategies that guide students’ thinking at different educational levels. We have used a qualitative research approach based on individual interviews with first-semester general chemistry (n=16), second-semester organic (n=15), advanced undergraduates (n=9), first year graduate students (n=14), and PhD candidates (n=16) to better characterize the evolution of students’ conceptual sophistication and modes of reasoning about chemical synthesis. Our results reveal a great variability in the cognitive resources and strategies used by students to make decisions, particularly at intermediate levels of expertise. Nevertheless, our data analysis has allowed us to identify common modes of reasoning and assumptions that seem to guide students thinking at different levels in their training. Our results should facilitate the development of learning progressions that help improve chemistry instruction, curriculum, and assessment.