In the past, there has been an implicit assumption that discussion threads in distance education courses develop according to the needs and interests of conference participants, the requirements of the course, and the nature of the instructor's online facilitation. The findings in this article suggest that other factors may also be at play. A large-scale analysis of threads and their growth patterns reveals a bias in favor of elongated note structures. This bias is explained by a tendency for computer conference users to focus on recently introduced notes and a reduced tendency to re-visit older, more established notes. Consequently, the most recent notes in each thread are the ones most likely to drive the next round of responses. Educationally, this situation can be problematic if an excessive focus on new notes unintentionally shifts attention away from important issues. Strategies for addressing these concerns are discussed.