Supporting graduate students in becoming effective educators strengthens the overall quality and impact of geoscience programs. At the University of Southern California, I expanded and formalized a structured, semester-long TA training program to support Earth science teaching assistants (TAs) in developing pedagogical skills, instructional confidence, and equitable teaching practices. The program begins with a required one-unit seminar in the graduate students' first semester that introduces evidence-based instructional strategies, inclusive classroom practices, and the common challenges faced in geoscience classrooms. This foundation is reinforced through weekly meetings that focus on upcoming course content, address instructional challenges, and integrate targeted teaching strategies that build across the semester. This timely support, combined with sustained pedagogical development, equips TAs to shape their classrooms to better support diverse student learning needs throughout the semester.
Since implementation, graduate students report increased confidence, stronger classroom management skills, and greater preparedness to support diverse learners. Undergraduate students benefit from more consistent instruction and a more equitable learning environment across course sections. This model demonstrates how intentional, department-level TA development can strengthen teaching culture and enhance the overall coherence and quality of undergraduate geoscience instruction.