Signals from Staff Notes: Investigating Diachronous Messages for Being a Laboratory Teaching Assistant

National reform documents have historically shaped how we as a research community understand students’ perspectives regarding the nature of chemical knowledge and its production. However, while scholars have investigated various facets of undergraduate learning, research on how teaching is enacted in higher education remains under-addressed. Such documents may also be less relevant for instructors such as laboratory teaching assistants who may rely on more local resources (e.g., documents from staff meeting) for their synchronous (during class) and diachronous (out of class) teaching practices. Accordingly, this study inductively and deductively coded diachronous messages from 22 staff notes from introductory chemistry at a large, research-intensive university to determine trajectories of teacher identities. Results showed that messages about facilitating student discussion and choice are minimal, with more instructions to follow a script and tend to the laboratory itself. In addition, messages from staff notes remained consistent, offering few opportunities for laboratory teaching assistants to experiment, customize, and improvise their instructional practices. Finally, two focal identities-in-practice were presented that not only problematize the trajectories of teaching assistant development but also raise concern for what is taught in the instructional laboratory. We conclude with recommendations to provide laboratory teaching assistants with chemistry-specific teacher moves. In addition, future research should investigate how synchronous laboratory teaching aligns with diachronous preparation and clarify the roles of “laboratory teaching assistant.”