Dr. Gresalfi’s research considers cognition and social context by examining student learning as a function of participation in activity settings. I conceptualize learning as a trajectory of a student’s participation in a community—a path with a past and present, shaping possibilities for future participation. Following a situative perspective on learning, I have investigated how opportunities to learn get constructed in mathematics classrooms, and how, when, and why different students take up those opportunities. This focus has enabled me to explore the extent to which classroom practices are equitable and to examine categories such as race, gender, and previous mathematical experience as they arise in interaction. Current projects continue to examine students’ mathematics learning in novel classroom contexts, including gaming environments such as Quest Atlantis, and project-based curricula such as New Tech High.