Cognitive processing of hyperdocuments: when does nonlinearity help?

This paper presents a review of empirical research on the cognitive processing of nonlinear documents, with the purpose of understanding when and how hypertext presentation might facilitate text comprehension and learning activities. Empirical studies conducted so far have used various methods, and foeused on a wide range of populations, types of documents, and reading or learning tasks. Alkhough hypertext is generally associated with information networks, a few interesting studies ad&ess the issues of computer assistance to linear text comprehension. A second group of studies investigate the use of nonlinear documents for general learning purposes. Although these studies are mainly concerned with linear-nonlinear comparisons, some of them address the effects of different design options. Finally,, a third group of studies compare information retrieval in linear versus nonlinear documents. Overall, there is no consistent evidence for the advantage of hypertext over linear presentation formats. Instead, the efficiency of nonlinear documents varies aeeording to (a) subjects’ expertise (b) interface features and (c) task requirements. In an attempt to provide an interpretative framework for these empirical findings, the notion of cognitive monitoring is briefly outlined. I conclude with a few implications for future hypertext reseamh. Permission to copy without fee all or part of this materisl 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 /0131/ $1.50