Towards a better support for hypermedia structuring: the HYDESIGN model

Hypermedia systems are becoming an important information system class for a wide range of new and fascinating applications. But current systems still have some unpleasant restrictions. For example, only few hypermedia systems support the design of higher level hypermedia objects beyond the basic node-link paradigm. There are further restrictions concerning the modukuization of the overall design and the reuse of (complex) hypermedia resources. HYDESIGN is the prototype of an extensible hypertext/ hypermedia system which adresses these restrictions. The crucial part of the development is the data management component, the HYDESIGN-engine, which has been built on top of the Gem Stone object-oriented database management system. A first prototype of a graphical user interface, the HYDE SIGN-GUI, has been developed in Smalltalk-80. This paper focuses on central features of the HYDESIGN data model representing the conceptual basis of the HYDESIGN-engine. Aggregate links of differefit types are introduced which allow for the creation of higher level hypermedia networks. SBLnodes represent particular composite nodes offering the capability of defining (nested) local environments with particular behaviour. Also different options for the sharing of hypermedia resources are proposed. HYDE SIGN further supports navigation as well as query based access in an integrated approach. As a whole, HYDESIGN aims at a better support for the hypermedia design process by the provision of powerful structuring facilities. Permission to copy without fee au 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 repubtish, requires a fee and/or specific permission. @1992 ACM &89791-547-X/92/~11 /0B2/ $1.50