Virtual hierarchies and virtual networks: Some lessons from hypermedia usability research applied to the World Wide Web

The paper considers the usability of the World Wide Web in the light of a decade of research into the usability of hypertext and hypermedia systems. The concepts of virtual hierarchies and virtual networks are introduced as a mechanism for alleviating some of the shortcomings inherent in the current implementations of the web, without violating its basic philosophy. It is suggested that virtual hierarchies and virtual networks will assist users to find task-relevant information more easily and quickly and also help web authors to ensure that their pages are targeted at the users who wish to see them. The paper first analyses the published work on hypermedia usability, identifying the assumptions that underlie this research and relating them to the assumptions underlying the web. Some general conclusions are presented about both hypermedia usability principles and their applicability to the web. These results are coupled with problems identified from other sources to produce a requirements list for improving web usability. A possible solution is then presented which utilizes the capabilities of existing distributed information management software to permit web users to create virtual hierarchies and virtual networks. Some ways in which these virtual structures assist searchers to find useful information, and thus help authors to publicize their information more effectively, are described. The explanation is illustrated by examples taken from the GENIE Service, an implementation of some of the ideas. This uses the World Wide Web as a means of allowing global environmental change researchers throughout the world to find data that may be relevant to their research. (C) 1997 Academic Press Limited.