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Hyper-Book: a Formal Model for Electronic Books

This paper presents a model for an electronic book (hyper‐book). Hyper‐books are electronic books defined on the basis of the paper book metaphor. This metaphor guarantees ease of use and understanding, as the paper counterpart is a well known concept. The hyper‐book maintains many of the features of paper books, in terms of interface design and available tools (orientation, navigation, personalisation) and provides added‐value that exploits the technology underlying it, such as searching, links and history mechanisms. We give a formal definition of the hyper‐book model as a dynamic system. The hyper‐book model is defined in terms of structural and functional components. Further, how the system evolves under the effects of these functional components is presented. The structural components reflect the book subdivision in pages, and the page subdivision in elements such as text, figure etc. The functional aspect is indispensable for describing the use of a dynamic and interactive system. In particular, a number of operators, which represent reader services, allow the user to change the system ‘state’. This simple model is intuitive, general and easy to extend. The hyper‐book model has been implemented in a working system, and evaluated with a group of users. The evaluation has confirmed that the adoption of the book metaphor is very effective, as it guarantees ease of using and understanding the system. The use of the hyper‐book model for organising and presenting electronic documents could have a considerable impact in the context of electronic publishing. A system, based on this model, could have a large applicability and diffusion in several fields such as electronic libraries, thanks to its user‐friendly interface.