This paper examines the role of discussion forums in MOOCs as platforms for social learning and knowledge propagation. By modeling forums as heterogeneous networks using social network analysis, the study identifies "representative students" who are highly engaged in discussions but do not necessarily exhibit exceptional learning behavior or performance. The paper suggests prioritizing these students' posts to enhance knowledge dissemination and improve teaching quality. A real-time visualization tool is developed to help instructors manage and respond to forum interactions effectively.