HYPER‐LIB: A FORMAL MODEL FOR AN ELECTRONIC LIBRARY BASED ON HYPER‐BOOKS

This paper presents hyper‐lib, a model for an electronic library. The hyper‐lib philosophy is based on reproducing the spatial environment of a physical library, in order to exploit users' knowledge of the physical domain in using the electronic system. In the library environment, rooms, shelves, books and services are reproduced by simulating a three‐dimensional environment, where the user can interact with a collection of documents as if he or she were in a physical library. In addition to the physical library features, the hyper‐lib introduces a number of new properties, which result from its non‐physical nature and allow some of the limitations of traditional libraries, such as availability of books and delivery time, to be overcome. The hyper‐lib books are available in electronic form, following the hyper‐book model, which is based on the book metaphor. A formal definition of the hyper‐lib model as a dynamic system is given. The hyper‐lib model is defined in terms of structural and functional components. Moreover, the functional behaviour, i.e. how the system evolves under the effects of the functional components, is presented. The library structural components include the book collection, the librarian, the access mechanisms etc. The functional aspect is indispensable for describing the use of a dynamic and interactive system. In particular, a number of operators, which represent user services, allow the user to change the system state. We distinguish among general services, which are offered in any room of the library, and specific services, which are specific to a particular object or room in the library, such as the librarian, the catalogues, the hyper‐books, the book shelves etc.