A city metaphor for supporting navigation in complex information spaces

A major problem in modern information systems is to locate information and to re-find information one has seen before. Systems like the Word-Wide Web are heavily interlinked but do not show structures that help users to navigate the information it contains. The use of appropriate navigation metaphors can help to make the structure of modern information systems easier to understand and therefore easier to use. We propose a conceptual user interface metaphor based on the structure of a city. Cities are very complex spatial environments and people know how to get information, how to reach certain locations in a city, and how to make use of the available infrastructure etc. Cities provide a rich set of navigational infrastructure that lends itself to creating sub-metaphors for navigational tools. A city metaphor makes this existing knowledge about a structured environment available to the user of a computerized information system. We first focus on several properties of future user interfaces (or user interface metaphors) that will distinguish them from current systems, like the richness of information or the use of visualizations to show the structure of information spaces. We also describe the strengths and problems of spatial user interface metaphors. Then we describe the structure of the information city metaphor, its structuring and navigation metaphors and what we see as its main advantages and problems. We further describe a few scenarios of how an Information City might work. Finally we compare implementing this metaphor using either a textual or graphical virtual environment or a combination.