Activity awareness support is a key feature for helping people to resume the state of their collaborations when switching among different tasks.
This paper proposes a visualization model supporting an incremental access to information, from an overview of the state of the user’s activity contexts to the details about the events occurred in each of them. The higher visualization layer is represented as a tag cloud and provides a general view of the degree of activity occurred in each context. The other levels are projections on the event history focused on specific perspectives; e.g., general collaboration, task or actor.
A user study showed that our visualization model outperforms standard awareness spaces which provide a direct access to awareness events because it enables users to retrieve the relevant information quicker and more precisely.