Expressive interactions - supporting collaboration in urban design

This paper discusses technological interventions in support of planners, citizens and other stakeholders in envisioning and nego-tiating an urban project. A set of prototypal tools, including a tangible user interface, has been developed that allow users to create and manipulate visual/auditory scenes and mesh these scenes with the real environment of an urban site. The paper dis-cusses how to support users – different types of stakeholders- in the collaborative creation of mixed reality configurations as an integral part of expressing their ideas about an urban project, dis-tinguishing between different types and levels of cooperation. It also looks into how to use mixed reality tools for enhancing an already highly developed representational culture.