The link vs. the event: activating and deactivating elements in time-based hypermedia

Activation and deactivation of media items plays a fundamental role in the playing of multimedia and time-based hypermedia presentations. Activation and deactivation information thus has to be captured in an underlying document format. In this paper we show that a number of aspects of activation and deactivation information can be captured using both link structures and events in time-based hypermedia. In particular, we discuss how deactivation and activation can be specified, how the activations and deactivations can be initiated and potential (synchronization) relationships between the elements involved. We first introduce the notions of time-based scheduling and event-based scheduling and then present a short summary of linking. We discuss the similarities between event-based scheduling and linking. We describe a number of aspects of activation and deactivation that can be specified within a document. We then discuss how activation and deactivation information can be recorded in link structures and events.