1.2 The Need for a Reference Model for IMMPS's

  Up to now, a lot of research and development addressed aspects of multimedia communication and particularly automated multimedia presentation generation. There are already examples of successful technology transfer from research lab prototype systems to industrial applications. However, no generic model for IMMPSs has emerged. Each project began from scratch, relying only on the past experience of the developers. Consequently there remains replication of results and limited re-use of previous solutions and limited synergy among parallel ongoing efforts. Among other things, there is no agreement on the terminology to be used, on the functional definition of an IMMPS, or on a generic architecture which reflects an implementation independent view of the processes required for the generation of multimedia presentations.

With the proposal for a reference model, this paper tries to fill a major methodological gap and thus may provide a sound basis for ongoing and future developments of IMMPSs. There are several advantages of an agreement on a reference model. The development and the analysis of systems will benefit from a uniform approach to the problem. The modular development of large-size programs will be feasible, as each module has a well defined role, with well defined interfaces and communication protocols with the other modules. From a theoretical point of view, the analysis and comparison of systems can now be made on the basic of a unique, general architecture and by means of a common terminology. These considerations are universally valid for any reference model. In the case of IMMPSs, however, they assume a deeper significance, as the literature with respect to the basic terminology remains confusing.

Also, we argue that existing reference architectures for user interfaces and user interface management systems (UIMSs) are not suitably refined to capture the details of IMMPSs. For example, the so-called Seeheim Model (cf. [1], and cf. Fig. 1) has gained considerable popularity among the designers of user interfaces. However, the Seeheim Model does not provide means for describing an IMMPS, except saying simply that an IMMPS is an instantiation of the presentation layer in the Seeheim Model. While in recent years several refinements have been made (e.g., the Arch Model - cf. [2]) none of them refines the original Seeheim presentation layer in sufficient detail to support informative characterizations of IMMPSs.

 

Figure 1: The Seeheim Reference Model for UIMSs