Abstract
There has been an increasing interest in designing tangible user interface (TUI) systems in the context of urban planning. However, little has been done in studying the usability of such systems. In this paper, we present an observational study on a collaborative TUI system to examine the usability of the system in the urban planning process and to investigate its effect on stakeholders’ engagement and decision-making. The study suggests that TUIs and physical objects encourage collaboration and communication among stakeholders, which lead to more informative decisions.