Abstract. Workspace awareness support is mandatory for group support systems. In this paper, we present a novel approach to asynchronous awareness by means of traceability support. We integrate and evaluate our approach in the web portal of CASTing, a tool for audio-based collaborative storytelling. We describe the development of a prototype that visualizes how the collaborative story evolved over time. Our visualization helps group members assess who has modified the shared story, what exactly has been modified and when it has been modified. We evaluate different awareness factors in an experiment. The experiment proved that our visualization approach enables users to acquire workspace awareness by accessing information about previous work of other users.