The Amsterdam Hypermedia Model: Extending Hypertext to Support Real Multimedia

We present a model of hypermedia that allows the combination of “hyper-structured” information with dynamic multimedia information. The model is derived by extending the Dexter hypertext reference model and the CMIF multimedia model. The Amsterdam hypermedia model allows the following, in addition to the model provided by Dexter: • the composition of multiple dynamic media, in order to specify a collection of time-based media making up a complete multimedia presentation; • the definition of channels for specifying default presentation information, allowing the specification of the presentation characteristics of nodes at a more general level than that for an individual node; • the composition of existing presentations into larger presentations, taking into account possible clashes of resource usage; • the inclusion of temporal relations while maintaining the separation of structure and presentation information, where time-based relationships are treated as presentation information; • the definition of context for the source and destination anchors of a link in order to specify the parts of a presentation affected on following the link. The Amsterdam hypermedia model enables the description of structured multimedia documents, incorporating time at a fundamental level, and extending the hypertext notion of links to timebased media and compositions of different media. The paper is organised as follows. The Dexter hypertext model and the CMIF multimedia model are summarised, and their limitations for use as a more general hypermedia model are discussed. The extensions included in the Amsterdam hypermedia model are described and a summary of the resulting model is given.