Dr. Langer-Osuna is assistant professor of mathematics education at the Graduate School of Education. She earned her PhD at the University of California, Berkeley and was a National Academy of Education/Spencer postdoctoral fellow. Her research focuses on how students develop identities as learners in collaborative mathematics classrooms, with a focus on the construction of authority, influence, and marginalization among peers. Dr. Langer-Osuna teaches in Stanford’s Teacher Education Program (STEP) and partners with local school districts to develop and study elementary teacher professional development for mathematics instruction in collaborative classrooms. She has worked with the National Assessment for Educational Progress (NAEP) and the California Mathematics Framework to bring attention to issues of identity and peer collaboration in state and national frameworks. Her work has appeared in the Journal of the Learning Sciences, Journal for Research in Mathematics Education, Review of Research in Education, and other top research journals in mathematics education research.