Abstract
Computer-mediated communication has become a major research topic due to the growing number of graduate-level students entirely or partially enrolled in Internet-based degree programs. Drawing on the concept of common ground from Clark's communication theory, we propose a model to investigate the varying quality and flow of online learning conversations. Our investigation centers on three discourse systems in order to isolate the effects of two functional differences: online presence of the learning material and a linking functionality. The first system, which supports parallel artifact-centered discourse, displays the learning material and its related discussion in a single window. The second system, which supports linked artifact-centered discourse, provides a bi-directional linking functionality between these two elements available in a single window. The control system, which supports conventional discourse, offers the two elements in separate windows. We conducted an experiment with 30 doctoral students enrolled in three sections of an introductory research methods seminar. A total of 30 discussion transcripts, 10 for each group, formed the basis of the data analyses. Using an integrated approach that combined content and sequential analyses, we categorized and sequentially plotted all messages. The findings demonstrate that the online presence of the learning material supports sustained discussions centered on understanding the meaning of a text. Moreover, a linking functionality promotes complex forms of interaction with the learning material and re-focuses the discussion when it digresses. We discuss the theoretical and practical implications of these findings.