Researchers in CSCL have used a wide range of qualitative and quantitative methods to track students' cognitive involvement during collaboration. However, neither individual method suffices the need to capture the dynamic evolvement of students' epistemic engagement in CSCL. We developed Epistemic Synchronization Index (ESI) to quantify students' epistemic engagement and evolvement. ESI reveals the knowledge elaboration process of groups, and it helps researchers as well as teachers to distinguish epistemic involvement between members within one group.
