This paper describes a detailed analysis of a problem-based learning group to understand how an expert facilitator supports collaborative knowledge construction. The study examines the questions and statements that students and the facilitator generated as they traversed a complex conceptual space. The facilitator tended to use open-ended metacognitive questioning and never offered new ideas. His contributions built on the students thinking. These moves helped support deep student engagement with conceptual knowledge. Several specific strategies were identified that supported the goals of helping students construct causal explanations, reason effectively, and become self-directed learners. Studying facilitation in a face-to-face situation provides some guidance in designing support to use in an online problem-based learning environment; however, considerable adaptation is necessary as some facilitation can be built into the system but other facilitation may need to be done by a human tutor. Implications for CSCL system design for problem-based learning as well as preliminary experience with an online PBL system is discussed.
['Cindy E. Hmelo-Silver']
Facilitating collaborative knowledge construction