Effects of different types of instructor comments in online discussions

The current study examined the effects of different types of instructor comments on student engagement in an online discussion. In particular, this study examined three comment types: (1) praise-oriented comments, agreeing with students' initial messages and recapping their ideas, (2) elaboration-encouraging comments, requesting elaboration on the initial messages, and (3) perspective-widening comments, suggesting different or thought-provoking opinions responding to the initial messages. Seventeen graduate students enrolled in an online course were recruited. A content analysis was employed to evaluate the levels of knowledge construction. Interactivity was measured by the number of posts and idea units. The findings revealed that perspective-widening comments facilitated students' evaluation on the peer postings and brought up diverse perspectives, contributing to knowledge construction. While elaboration-encouraging comments led to high interactivity among students, praise-oriented comments had no significant effect on the frequency of interactivity.