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With rapid advances in and convergence of such technologies as advanced workstations, computer networks, optical disk storages as well as artificial intelligence, an active document, as it is proposed in this paper, will become a new reality in the near future.As with hypermedia information systems known to us today, an active document organises and represents multimedia information non-linearly in terms of a collection of nodes and links among the nodes, where nodes represent such diverse objects as concepts, unstructured text, graphics, images or voice message, and links denote some kind of relations among these objects. However, among others, the active documents extends hypermedia systems in the following important ways:
- An active document changes both its content and the form in which the selected content is presented automatically, depending on who is reading it, and when and in which context it is read. This is accomplished by building into the active document a context sensitive user model for prospective readers and by classifying them into various classes with different authorisation privileges, different information needs, different levels of user skills, etc.
- An active document is inter-operable (ie highly portable) cross many different hardware and software platforms, and the form in which the content of the active documents is presented is determined by features of its underlying hardware and software platform. That is, an active document can be presented in simple mono colour display as well as a sophisticated multimedia workstation, all be that the content of the document is presented in a different form. In contrast to the above, an active document also relies on a model of its underlying presentation and manipulation media.
- An active document is capable of automatically updating and changing its content according to events or changes which occur in other components of the information system to which the active document is interconnected, as simply as a result of passage of time. The former kind of update and change is passive in the sense that it happens as a result of other events and changes, while the later is active as it originates by itself at some pre-specified point of time. But, in either case, the update and change of the content of the active document may lead to chained action onto other components interconnected to it within the organisation. This is achieved by embedding selected information items of the active document with active demon processes and rules which monitor the change of the value of the information items and then invoke proper actions accordingly.
Documents in business and office communication are predominantly composed of such semi-structured, semantically rich generic objects as forms, tables, figures, concepts, people etc. Thus from the information processing point of view, it is both desirable and convenient to treat these generic objects as active objects in the object oriented programming paradigm, where the behaviour of the each object can be defined in terms of a set of attributes and a collection of methods defined over the attributes, and where the objects with similar behaviours are grouped into classes. Indeed, the key idea of the concept of the active document is that an active document is composed of a collection of such active objects whose behaviours are dynamically changeable chronologically and as a result of changes of interrelated objects.
Currently, we are in the process of designing and implementing a prototype of an active document. Specifically in this paper, we will first motivate the need for such an active document and discuss its enabling technologies, then describe and open architecture for the active document and detail main components of the active document. Finally, we will discuss the mechanisms used and issues in implementing the active document.
| Author: Xiao-Dong Xia, Artificial Intelligence Section, Telecom Research Laboratories, PO Box 249, Clayton Victoria 3168, AUSTRALIA. Email: xia@trlamct.trl.oz.au
Please cite as: Xia, X. (1992). Beyond hypermedia: Design and implementation of an active document system. In Promaco Conventions (Ed.), Proceedings of the International Interactive Multimedia Symposium, 173-174. Perth, Western Australia, 27-31 January. Promaco Conventions. http://www.aset.org.au/confs/iims/1992/xia.html |