The issue of incorporating semantics into a hypertext network has been addressed before [7,25]. Rao and Turoff had proposed a general framework for hypertext functionality based on Guilford's Structure of the Intellect Model [20]. They had observed that as hypertext databases grow in size, they suffer from a lack of coherence due to ambiguity in meanings assigned to nodes and links. Hence, they proposed a framework which classified nodes into six different semantic types and links into twelve different types. Such a comprehensive framework would help designers develop better design metaphors and implementation models for hypertext systems. A first step in this direction is to develop an appropriate user interface which would reduce functional and system opacities.
A number of tools have been developed for hypertext navigation since Conklin addressed the issues of disorientation and cognitive overhead [8]. These include graphical browsers, overview diagrams, web views, paths, trails, guided tours and tabletops, history lists, timestamps, footprints, bookmarks, backtracks, queries, embedded menus, fisheye views and roam and zoom techniques [ 3, 7, 11, 13, 17, 24, 28, 30 ]. Authoring guidelines have also been proposed for the organization of information in a hypertext system [23]. However, there has been no systematic and comprehensive approach towards the design of user interfaces for hypertext systems. This paper attempts to explore the application of a set of user interface design guidelines to the aforementioned hypertext framework.
Rao and Turoff had claimed that all current hypertext systems fall under their hypertext framework and their semantic morphology can be extended to all future systems [20,26]. Since the user interface guidelines have been applied to such a general framework, we believe that these guidelines encompass user interface designs for all current and proposed hypertext systems. The next step is to determine the effectiveness of this approach by developing a user interface prototype for the discussed hypertext framework and conducting usability experiments.
Very little work has been done towards a systematic and comprehensive approach to the design of a user interface for a hypertext system using traditional and modern user interface design principles. This paper proposed the application of a set of user interface design guidelines to a hypertext framework developed earlier. It has been suggested that the understanding of how people use their cognitive skills to handle information will greatly enhance the design and evaluation of hypertext systems [29]. We believe that a user interface design based on the above systematic approach combined with the semantic richness of nodes and links would greatly reduce ambiguity, disorientation, and cognitive overhead. We need such an approach in order to integrate hypertext applications into our daily work in an increasingly collaborative environment.