A proposal of reference model

ion a process that transforms information into information whose semantic content and scope are richer/higher than the content and scope of the initial information. Discussion Other terms We do not claim that this list of terms is complete. Several other notions e.g., cross-media references, coherency between media, anaphoru, cliexis, ,redundancy, etc. are currently used. Nevertheless, an extensive characterization of media terms is out of the scope of this paper. We restrict ourselves to consider a set of very basic terms, which should be sufficient for our purposes. Information carrier, carried item and substrate The information carrier of a particular simple exhibit may be different for the producer and the consumer of that exhibit. The same can happen for the notions of carried item and substrate. When this mismatch arises the communication between producer and consumer is likely to fail. 2.2 Presentation systems In the following we introduce the fundamental notions of gods and ,wesentation systems, These are designed for achieving goals by means of a presentation. goal a high level description of a collection of data together with the purpose or intention for communicating information. achieving a goal presenting to the user the data described by a. goal in a way that achieves the purpose or intention for communicating information. presentation the result, perceivable by the user, of achieving a goal. presentational command a command to the system whose execution affects the 'presentation process (ex., any-time interruptions, design constraints, etc.) application the external system producing application data as input to the presentation system. goal formulation the external system producing goals and presentational commands as input to the presentation system. presentation system a system for achieving goals and executing presentational commands. rendering function of transforming an internal logical representation of a presentation in the primitives of a set of devices. devices interfaces between the presentation system and the user. Generally, they are the physical artefacts necessary to the system to deliver the presentation (e.g., display, speaker, printer etc.) 2.3 .Adding knowledge 5 user a person interpreting a presentation. multimedia presentation systems a presentation system that generates multimedia presentations. Discussion Goal formulation system (e.g., let the user be aware of some information, etc.) Actually, the purpose to communicate information can be partly embedded in the presentation User as a person The definition of user could be stated requiring a user to be any external object interpreting a presentation. In principle, indeed, it could be another computational system. However, as we are dealing with high-level communications it seems correct to assume the user to be a person. Presentational commands Through these commands, we model requests like interruptions of the presentation process, or communications of constraints, etc. These interactions are hardly formalizable in terms of the only notion of goal. 2.3 Adding knowledge The last point towards a full definition of IMMPSs is to introduce the notion of knowledge. This is fundamental in order to characterize IMMPSs as “intelligent” systems and to differentiate them within the larger class of presentation systems. knowledge justified true beliefs of an abstraction of data. knowledge sources the following explicitly encoded knowledge: user model knowledge about the user (goals and plans, capabilities, attitudes, knowledge or belief.) context model knowledge about the context (discourse model, context references .) application knowledge knowledge provided by the application and knowledge for reasoning about application data (term interpretation, data characterization.) design knowledge general knowledge about the design of multimedia presentation (design constraints, cognitive theory, media model, device model.) media specific design/realization knowledge knowledge about the design/realization for a specific media in a multimedia presentation. 6 2. PRESENTATION SYSTEMS system model knowledge about the system’s characteristics relevant to the presentation process. media selection knowledge knowledge for identifying an effective and coordinated collection of media for the representation and presentation of application data. intelligent multimedia presentation system (IMMPS) a multimedia presentation systems that designs a presentation exploiting the knowledge sources to achieve goals. Discussion Other knowledge sources The knowledge present in an IR PS may include other explicitly encoded knowledge 1 ian those described as knowledge sources. For instance, we will discuss in section 4.2 that a planning and a content selection knowledge might be present in a system. However, the classified knowledge sources seem to be the most relevant knowledge, and the most used in real application. Therefore, we defined IMMPSs as systems exploiting at least the knowledge sources. Additional knowledge may be present and often is but we do not force it to be in every IMMPS. . Intelligence of an IMMPS The degree of knowledge exploited in an IMMPS gives an idea of how “intelligent” it is. Unfortunately, it is impossible to give a formal definition of a “measure of intelligence”, as it depends on how well the goals are fulfilled. This “how well” is related to the user perception and understanding of the presentation, and then it is a relative concept. IMMPSs and presentation systems It is worth noting that there is no difference between IMMPSs and presentation systems with respect to their interface with the goal formu1at)ion. This component does not have to know whether or not the presentation systems is “intelligent”, in order to generate a goal. The alternative choice of differentiating the interface for IMMPSs would not be modular, since it would not allow to replace a presentation system with a (further revised) intelligent presentation system.