Phenomenon: Problem-based learning (PBL) has been widely adopted in medical schools across the globe. However, the dynamics of discourse moves in time sequences during such learning remain underexplored. This study investigated discourse moves used by PBL tutors and tutees to facilitate collaborative knowledge construction, and adopted sequential analysis to unpack the temporal dynamics of such moves during PBL knowledge construction in an Asian context. Approach: This study's sample comprised 22 first-year medical students and two PBL tutors at an Asian medical school. Two 2-h PBL tutorials were video-recorded and transcribed, and notes were made about the participants' non-verbal behaviors, including but not limited to body language and technology use. Descriptive statistics and visual representations were used to discern participation patterns as they evolved over time, and discourse analysis was applied to identify specific types of teacher and student discourse moves within knowledge construction. Lastly, lag-sequential analysis (LSA) was adopted to understand the sequential patterns of those discourse moves. Findings: The PBL tutors mainly used probing questions, explanation and clarification, compliments, encouragement, affirmation, and requests when facilitating PBL discussions. LSA revealed that discourse moves had the following four major paths. Teachers' content-related questions elicited both lower- and higher-level thinking from students; teachers' statements mediated between students' thinking levels and teachers' questions; there were relationships among teachers' social-facilitation discourse, students' thinking modes, and teachers' statements; and there was a sequential relationship among teachers' statements, students' facilitation, teachers' process-related discourse, and students' silences. Insights: This study revealed the importance of using probing questions to facilitate students' knowledge construction as they proceeded from lower- to higher-level thinking. This study also fills a gap in the current literature by adopting the innovative LSA methodology to explore teachers' and students' discourse move sequences in PBL. The results have important practical implications for PBL tutors regarding when and how to facilitate their students' collaborative knowledge construction.
Keywords: Problem-based learning; collaborative knowledge construction; lag-sequential analysis.