Implementing a course-based authentic learning experience with upper- and lower-division physics classes^a)

We describe a dual-class authentic learning experience (ALE) in which undergraduate upper-division physics students develop low-cost instruments, which are then used by students in a lower-division course to monitor water quality in rivers. The ALE bridges the experiences of lower- and upper-division physics majors by involving students across different stages of their college careers in a collaborative project. Lower-division physics students characterize, calibrate, and troubleshoot the instrument prototypes developed by their upper-division peers, and their work informs instrument modifications in future upper-division physics classes. This paper describes the first iteration of this project along with student perceptions. We find that lower-division students report an increase in their awareness of possible upper-division projects, an increased sense that their coursework has real-world applications, and a heightened understanding of how physicists can play a role in research on environmental issues.