CBE—Life Sciences Education Modeling Sources of Teaching Self-Efficacy for Science, Technology, Engineering, and Mathematics Graduate Teaching Assistants

have a large impact on undergraduate instruction but are often poorly prepared to teach. Teaching self-efficacy, an instructor’s belief in his or her ability to teach specific student populations a specific subject, is an important predictor of teaching skill and student achievement. A model of sources of teaching self-efficacy is developed from the GTA literature. This model indicates that teaching experience, departmental teaching climate (including peer and supervisor relationships), and GTA professional development (PD) can act as sources of teaching self-efficacy. The model is pilot tested with 128 GTAs from nine different STEM departments at a midsized research university. Structur-al equation modeling reveals that K–12 teaching experience, hours and perceived quality of GTA PD, and perception of the departmental facilitating environment are significant factors that explain 32 % of the variance in the teaching self-efficacy of STEM GTAs. This model highlights the import-ant contributions of the departmental environment and GTA PD in the development of teaching self-efficacy for STEM GTAs. Article charge of laboratory or recitation sections, in which they of-ten have more contact and interaction with the students than the professor who is teaching the course (Abraham et al.