This paper presents a synchronization model for hypermedia presentations. Several media, continuous, like video or audio file, or non-continuous, like text pages or images, are delivered separately over a network in a Web-based environment, and presented to the user in a coordinated way.

In this paper we discuss variability modelling for hypermedia applications. Inspired by domain engineering, we propose a domain engineering based method for hypermedia development. Since several adaptive hypermedia become more and more popular to incorporate dierent information views for dierent audience or environments, we believe that it is important to move variability capturing to modelling phases. Several established modelling views of hypermedia application are discussed from the variability point of view. We also explain modelling techniques by means of examples for the application domain view, the navigation view, the presentation view and discuss importance of the user/environment view for parametrisation of components.

Modelling is an important activity in the development of complex systems. Hypermedia modelling is a relatively new direction of research. Based on achieved results in software systems development, the recognition of importance of hypermedia modelling took relatively short time from the time of widespread adoption of hypermedia systems.

This paper presents a synchronization model for hypermedia applications. Several media, continuous, like video or audio file, or non-continuous, like text pages or images, are delivered separately over a network in a Webbased environment, and presented to the user in a coordinated way. The model is based on a set of synchronization relationships which define objects behavior during presentation's playback, and channels in which to play each object. The model is suited for a wide range of hypermedia documents type: some examples are self and distance education, professional training, Web advertising, cultural heritage promotion and news-on-demand. A virtual exhibition is analyzed as a test bed to validate the model. Keywords: Hypermedia authoring, World Wide Web, media delivery and synchronization, interactive presentation. 1

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Abstract. A multimedia report is a multimedia presentation which integrates data returned by one or more queries to a multimedia database, thus extending the concept of report familiar in traditional structured databases. In such a scenario information retrieval consists in building a continuous presentation in which the retrieved data are located, connected, synchronized and coherently presented to a user. We discuss modelling of multimedia reports in terms of data co-ordination and synchronization, based on a synchronization model we have defined for specifying complex multimedia presentations. As in a report the user can browse the returned data without loosing consistency, in a multimedia report moving along the presentation time requires appropriate synchronization to be guaranteed. 1

This paper discusses some issues related to authoring and navigating World Wide Web documents composed of continuous and non-continuous media, based on a video or audio narration to which static or dynamic documents are attached. The discussion stems from a model able to describe synchronization among media elements and media behavior depending on user interaction. A prototype implementation addressing SMIL as a target language is described.

Abstract. In this paper we discuss variability modelling for hypermedia applications. Inspired by domain engineering, we propose a domain engineering based method for hypermedia development. Since several adaptive hypermedia become more and more popular to incorporate different information views for different audience or environments, we believe that it is important to move variability capturing to modelling phases. Several established modelling views of hypermedia application are discussed from the variability point of view. We also explain modelling techniques by means of examples for the application domain view, the navigation view, the presentation view and discuss importance of the user/environment view for parametrisation of components. 1