Over the past 2 decades, increases in high school graduation and college entry requirements have pressed schools to teach more advanced mathematics to a broader range of learners. To some educators, this situation seems untenable: How can we simultaneously increase rigor in and access to this notoriously challenging subject?

One pedagogical approach that has been shown to increase rigor in and access to mathematics is a form of groupwork known as complex instruction. This approach has been shown not only to narrow or eliminate achievement disparities among student demographic subgroups but also to create positive mathematical identities for many learners, thus supporting students' overall sense of academic competence.

Because of these positive outcomes, there has been a growing interest in developing collaborative secondary mathematics classrooms. Recognizing that ...