Our work focuses on a traditional graduate course paired with online asynchronous forum that involved engineering students. The number of students in the course was larger than expected and the forum was suggested to all students as a way to interact between students and with the teacher. We use network analysis to look for central students in the network of the interactions within the forum and then interview two of the most active students to better understand their use of this technological tool. In this paper, we present our findings with the network analysis and the feedback the students gave us to understand the reason why they use the forum.