Clickers and peer instruction have been instrumental in enabling greater levels of student engagement in classrooms across the country. But any educational technique is necessarily modified – whether intentionally or not – when any particular instructor gives it a try in their classroom context. Thus, many researchers are studying peer instruction in greater detail, in order to better inform instructional practice. I will outline three separate research threads on these topics at CU-Boulder: How instructors at various institutions are using peer instruction, what students report works best for them, and which aspects of the technique have been shown to be important for student learning. Implications for instruction will be discussed.