In this paper, we assess collaborative learning facilitated by computer-mediated communication (CMC) systems in academic education. We examine collaborative learning as a process of knowledge construction. We present four studies that all took place as part of an academic course, in which students had to work collaboratively on complex tasks by the use of a CMC system. The four studies involved different tasks, students, tutors and CMC systems. In each study, we analysed how students constructed knowledge together and we related these findings to some main factors in the educational context: the role of the student, peer-student, tutor or moderator, and characteristics of the CMC systems used. The results showed that effective use of educational technology to support collaborative learning in academic education relates to these factors, including the modes of communication in asynchronous and synchronous CMC systems. Besides the need for more transparent and user-friendly CMC systems, asynchronous media can provide student groups with more options to think and reflect on information, to organise and keep track of discussions and to engage in large-group discussions compared to synchronous media.