Abstract
Students often experience science, technology, engineering, and mathematics (STEM) courses as competitive, weed-out spaces. Learning Assistants (LAs) have potential to improve students' experiences in these courses. Previously, we elucidated themes describing the impact of LAs on students' sense of STEM belonging and science-related confidence in introductory biology and general chemistry. Here, we expand our analysis to determine impacts of LAs on student belonging and confidence across science courses varying in structure, placement in students' academic trajectory, and discipline. Analyzing 1146 responses to questionnaires from seven classes revealed themes consistent with previous findings across all course structures and disciplines. However, impacts varied based on how LAs were integrated and students' typical class standing. Classes in which students had extended time in LA groups highlighted LAs' role in decreasing student isolation, whereas structures in which LAs were interspersed with lecture emphasized their role in providing feedback. Additionally, in courses that students take early in their STEM trajectory, LAs encouraged students through challenges, while LAs in later classes provided advice on STEM pathways. These results indicate the mechanism of LA impact varies depending on course context. Knowing how impacts vary across courses allows instructors and LAs to tailor their support, promoting the development of more inclusive STEM classrooms.