Fishing for clarity in hyperdocuments with enhanced fisheye-views

Abstract

It is known that fisheye-views prove beneficial to users who get lost in hyperspace. Until now, the fisheye-view strategy, introduced by Furnas, is only applicable in structures where the necessary components of the fisheye-view function can be defined. Unfortunately, directed graphs are structures where the fisheye-view function of Furnas cannot be applied. Therefore the fisheye-view concept was of limited value in hyperdocuments represented by such graphs. To overcome this lack, this paper proposes an enhancement of Furnas' function to allow its application in hyperdocuments of that kind. We will begin with a short review of Furnas' well-known fisheye-view concept. Thereafter, we will discuss the problems that arise when one attempts to apply the concept in so-called ..unstructured" hyperdocuments. The results of this discussion lead to the development of a function which satisfies the requirements of the concept, and allows its use in hyperdocuments of almost any structure. To show that the fisheye-view concept of Furnas remains fullfilled, an appropriate theorem is formulated. The result is that the benefits of the fisheye-view concept can now be appreciated in unstructured" hyperdocuments. In closing, we offer a detailed example, which illustrates the behavior of the enhanced fisheye-view function.