Collaboration at Work and Play -- Understanding Interaction in Ubiquitous Guerrilla Performances in Playful Arenas -- Towards the Development of CSCW: An Ethnographic Approach -- An Evaluation of Workspace Awareness in Collaborative, Gesture-based Diagramming Tools -- Layers -- An Empirical Comparison of Transparency on One and Two Layer Displays -- User Interface Overloading: A Novel Approach …