This article presents the results of a multi-site study conducted by nine graduate educators in the United States investigating how reading comprehension might be supported by social annotation. This research examines collaborative learning and group construction of knowledge that took place in six classrooms across a university semester. The findings of this study provide insight into the general reading comprehension practices of graduate students. The results also demonstrate how social annotation can operate as a pathway for understanding learning in process. We hope this study can act as a catalyst for discussion in the development of students' metacognitive practices.