Supporting Classroom Discussions Using a Trust-enhanced Private Backchannel

Classroom discussions between students or with the instructor can help them clarify the complicated or less clear mat erials of lectures and deepen their understanding; however student ini tiated discussions are not always encouraged in the classr ooms, because of the fast-pace of the lectures, fear of asking du mb questions, or the large number of students in the classrooms. Cla ssroom digital backchannels in the form of public chat-rooms have been used to address this problem, but mainly due to increasing distractions they are not widely adopted. In this paper, we intr oduced a trust- based backchannel system as an augmentation over private chat system, that enables users communicate with a group larger than the group of close friends and virtually access the knowledge of all students in the classroom, like in public chat, but with less distraction due to smaller number of interruptions. The initiated discussions are routed in the students' personal tr ust-networks according to the expressed and inferred trust relat ionships between students. The instructor interface of the proposed system provides awareness of the backchannel discussions including backchannel's activity level and the frequent keywords of the dis cussions. The proposed system is compared to a private chat syste m in a pilot mixed-methods study by 5 students during two 45-minute lectures and the combination of qualitative and quantitative results suggest that students found it helpful as a feature on basi c private backchannels, but not as a substitution.