A graph-based interface to complex hypermedia structure visualization

Complex hypermedia structures can be difficult to author and maintain, especially when the usual hierarchic representation cannot capture important relations. We propose a graph-based direct manipulation interface that uses multiple focus+context techniques to avoid display clutter and information overload. A semantical fisheye lens based on hierarchical clustering allows the user to work on high-level abstracts of the structure. Navigation through the resulting graph is animated in order to avoid loss of orientation, with a force-directed algorithm in charge of generating successive layouts. Multiple views can be generated over the same data, each with independent settings for filtering, clustering and degree of zoom.While these techniques are all well-known in the literature, it is their combination and application to the field of hypermedia authoring that constitutes a powerful tool for the development of next-generation hyperspaces.A generic framework, CLOVER, and two specific applications for existing hypermedia systems have been implemented.