With large student enrollment, MOOC instructors face the unique challenge in deciding when to intervene in forum discussions with their limited bandwidth. We study this problem of instructor intervention. Using a large sample of forum data culled from 61 courses, we design a binary classifier to predict whether an instructor should intervene in a discussion thread or not. By incorporating novel information about a forum’s type into the classification process, we improve significantly over the previous state-of-the-art.
We show how difficult this decision problem is in the real world by validating against indicative human judgment, and empirically show the problem’s sensitivity to instructors’ intervention preferences. We conclude this paper with our take on the future research issues in intervention.