TOCPN: interactive temporal model for interactive multimedia documents

Recently, much attention has been paid to interactive temporal models which let authors define possible interactions with users and represent the dynamic organization of hypermedia documents. The possibility of user interaction makes it very hard for authors to predict the course of presentation and to author a document without an authoring tool. The authoring tool must then be designed with a rich model representing the dynamic temporal structure of interactive multimedia documents. This temporal structure model should be able to specify both the temporal composition of interactive documents and their synchronization. We investigate possible user interactions and we design a new interactive temporal structure model based on the time interval model called the "transitional object composition Petri net" (TOCPN). The novel features of the TOCPN include the capability of expressing the dynamic structure of interactive multimedia documents, providing a synchronization mechanism for various media with various temporal relations, supporting sharing and reusing of existing objects, and supporting composite objects as well as atomic objects. In this paper, we also define the requirements of the authoring tool and its help tools, and we provide a preliminary architecture for the authoring tool.