Disorientation and Cognitive Overhead in Hypertext Systems

Disorientation and cognitive overhead are two interrelated problems that may in fact ultimately limit the usefulness of hypertext. Cognitive overhead upon the author arises from a viewpoint that sees the author as the person solely responsible for inserting all links within her work. This includes all links between the anchors in her own work and those in external frames, as well as cross-links between the anchors within her own work. The need for an author to be aware, for each anchor within her work, of all possible other anchors makes the insertion of such links an O(N 2) problem where N is the number of possible anchors in the hypertext universe. To reduce this to an O(N) problem this paper proposes the use of bi-directional intelligent anchors. These are anchors that have both a knowledge of the concepts that a potential reader would be seeking were she to arrive at the anchor, together with a knowledge of the concepts that a reader would be seeking were she to jump from that anchor to another within the hypertext. Disorientation or the lost in hyperspace eeect on the reader can be addressed in many cases by a fundamental re-deenition of the relationship between hypertext authors and their readers. To address this issue, this paper proposes a unit of authorship based more on the treatise than on the traditional fragmented model of hypertext that we call a scenic route and which is based loosely on Bush (1945)'s Trails and Trigg (1988 and 1991)'s Guided Tours.