This study examines the relationship between log data of student activity in learning management systems and self-reported student engagement survey scores. Log data has the potential to serve as a meaningful proxy for survey scores. Should this be the case, log data could be used as a minimally disruptive and scalable approach to quickly identify who needs help, evaluate design, and personalize instruction. We correlated LMS log data variables to student engagement survey scores to study the relationship between these two sources of data. Overall, log data was not a statistically significant proxy measure of students' self-reported cognitive and emotional engagement. Our results underscore the complexity of learning and the relationship between observed and reported cognitive and emotional states. Future educational research using log data will need to account for other factors that help explain trends in student engagement. Exploring the Potential of LMS Log Data as a Proxy Measure of Student Engagement.