Fishing for clarity in hyperdocuments with enhanced fisheye-views

Fishing for Clarity in Hyperdocuments with Enhanced Fisheye-Views K. Tochtermann, G. Dittrich UniversiQ of Dortmund Department of Computer Science, LS 1 P.O. Box 500500 D-4600 Dortmund 50; Germany e-mail: tochterm@jupiter.i?glormutik.um”-dortmund.de Phone: ++49-231-7556326 It is known that fisheye-views prove beneficial to users who get lost in hyperspace. Until now, the fisheye-view strategy, introduced by Fumas, 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 hyperdoeuments of that kind. We will begin with a short review of Furnas’ well-known fisheye-view concept. Thereafter, we wilt 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 Fumas remains fulfilled, 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. Permission to copy without fee all or part of this material is granted provided that copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific permission. @1992 ACM O-89791-547-X/92 /0011/0212/ $1.50