Beyond Time-on-Task: The Relationship between Spaced Study and Certification in MOOCs

A long history of laboratory and field experiments have demonstrated that dividing study time into many sessions is often superior to massing study time into few sessions, a phenomenon known as the "spacing effect." We use this well-established finding from the psychology literature as inspiration for investigating how students distribute their study sessions across an entire Massive Open Online Course (MOOC). Drawing on observational tracking log data from 20 HarvardX courses, we examine the relationship between students' allocation of their time in MOOCs and their performance. While controlling for the effect of total time, we show that the number of sessions students initiate is correlated with certification rate, across students in all courses. A one-unit change in session count is positively associated with an estimated 3.4% change in certification odds. When individual students spend similar amounts of time in multiple courses, they perform better in courses where that time is distributed among more sessions, suggesting that the benefit of spacing MOOC study sessions is independent of student characteristics. Our study demonstrates that well-established learning theories can be combined with massive new datasets and innovative approaches to learning analytics to advance our understanding of student practice and learning.