Online learning environments offer new opportunities for learning and over the last decade or so a variety of online learning environments have been developed by researchers to facilitate collaborative learning among students. In this paper we will present a case study of a successful collaborative learning design. This involves a near synchronous online seminar where students work in small groups to produce a report that examines media coverage of controversial science, using archives of television news reports. We will analyze the activity's task design features by employing a framework of collaboration enabling design approach proposed by Kirschner et al (2004). We will start with an analysis of the collaborative processes and interaction among participants in this online activity. Then we will examine the features of the task used in this learning environment with respect to the interaction design ideas proposed by Kirschner et al. They suggest that the use of appropriately designed and implemented educational, social and technological affordances is the foundation for stimulating, motivating and maintaining collaboration among learners. We use the framework to identify factors contributing to the success of the activity.