This article reports on findings from a mixed-methods validation study of the "Online Survey of Students' Experiences of Learning in Learning Communities". In the quantitative part of the study, we found strong correlations among survey items related to faculty behaviors, student behaviors, and critical thinking. Factor analysis yielded four primary factors: faculty behaviors that support quality learning for all students; student behaviors that foster responsibility for their own learning; student behaviors that support collaborative learning; and, student and faculty behaviors that together create an academic learning community. For the qualitative part of the study, we worked with LC programs at four institutions to investigate whether students think about the survey items in the same way we do. These findings--and an in-depth analysis of student responses at one campus--led to unexpected outcomes and new insights regarding LC assessment, specifically what students are learning from one another. In response, we developed a companion tool to the online survey, the "Peer-to-Peer Reflection Protocol." We conclude by addressing the potential of this guided discussion protocol to surface students' experiences of individual and collaborative learning.