Handbook of Multimedia for Digital Entertainment and Arts- P4

Handbook of Multimedia for Digital Entertainment and Arts- P4: The advances in computer entertainment, multi-player and online games,technology-enabled art, culture and performance have created a new form of entertainmentand art, which attracts and absorbs their participants. The fantastic successof this new field has influenced the development of the new digital entertainmentindustry and related products and services, which has impacted every aspect of ourlives.
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Handbook of Multimedia for Digital Entertainment and Arts- P43 Semantic-Based Framework for Integration and Personalization 77 Via the User Model Service (UMS) it is possible to set both context-independentvalues like e.g. ‘the user’s birthday is 09/05/1975’ or ‘the user has a hearing disabil-ity’ as well as context-dependent values like ‘the user rates program p with value 5in the evening’. However, all these statements must adhere to the user model schema(containing the semantics) which is publicly available. In this way, the system ‘un-derstands’ the given information, and is thus able to exploit it properly. If the systemfor example needs to filter out all adult content for users whose age is under 18 yearsold, the filter needs to know which value from the user profile it needs to parse inorder to find the user’s age. Therefore, all the information added to the profile mustfit in the RDF schema of the user model. However, since we are working with publicservices, it might be that an application wants to add information which does not fityet in the available schema. In that case, this extra schema information should firstbe added to the ontology pool maintained by the Ontology Service. Once these extraschema triples are added there, the UMS can accept values for the new properties.Afterwards, the FS can accept rules which make use of these new schema properties.ContextLike previously mentioned, in order to discern between different situations in whichuser data was amassed we rely on the concept of context. The context in which anew statement was added to the user profile tells us how to interpret it. In broadersense, context can be seen as a description of the physical environment of the useron a certain fixed point in time. Some contextual aspects are particularly importantfor describing a user’s situation while dealing with television programs: Time: When is a statement in the profile valid? It is important to know when a specific statement holds. A user can like a program in the evening but not in the morning Platform/Location: Where was the statement elicited? It makes a difference to know the location of the user (on vacation, on a business trip, etc.) as his interests could vary with it. Next to this we can also keep the platform, which tells us whether the information was elicited via a website, the set-top box system or even a mobile phone Audience: Which users took part in this action at elicitation time? If a program was rated while multiple users where watching, we can to some extent expect that this rating is valid for all users presentNote that context can be interpreted very widely. Potentially one could for examplealso take the user’s mood, devices, lighting, noise level or even an extended socialsituation into consideration. Where this in theory indeed could potentially improvethe estimation of what the user might appreciate to watch, in our current practicemeasuring all these states is considered not very practical with current technologiesand sensor capabilities.78 P. Bellekens et al. Working with context is always constrained by the ability to measure it. TheUMS allows for client applications to enter a value for these three aspects (time,platform/location, audience) per new user fact added. However, the clients them-selves remain responsible to capture this information. Considering the impact ofcontext on personalization in this domain, it would be very beneficial for the clientapplications to try to catch this information as accurate as possible.EventsPreviously, we made the distinction between context-independent and context-dependent statements. We will refer to the latter from now as ‘Events’ because theyrepresent feedback from the user on a specific concept which is only valid in a cer-tain context. This means that for every action the user performs on any of the clients,the client can communicate this event to the UMS. We defined a number of eventswhich can occur in the television domain like e.g. adding programs to the user’s fa-vorites or to the recording list, setting reminders and/or alerts for certain programs,ranking channels, rating programs, etc. All different events (modeled as the classSEN:Event) are defined in the event model as shown in Figure 5. Each event hasa specific type (e.g. ‘WatchEvent’, ‘RateEvent’, ‘AddToFavoritesEvent’, ‘Remove-FromFavoritesEvent’, etc.), one or more properties, and occurs in a specific contextas can be seen in the RDF schema. Each event can have different specific proper-ties. For example, a ‘WatchEvent’ would have a property saying which program wasFig. 5 Event model3 Semantic-Based Framework for Integration and Personalization 79watched, when the user started watching and how long he watched it. Since all theseevent properties are so different from each other, we modeled this in a generic wayby the class ‘SEN:EventProperty’. This class itself then has a property to model itsname, value and data type. The SEN:Context class has four properties modeling the contextual aspects asexplained above. The SEN:onPlatform property contains the platform from whichthe event was sent, SEN:onPhysicalLocation refers to a concept in the Geonamesontology which will only be filled in once we are able to accurately pinpoint theuser’s location. The SEN:hasTime property tells us the time of the event by referringto the Time ontology and with the SEN:hasParticipant property we can maintain allthe persons which were involved in this event. All the information we aggregate from the various events, is materialized in theuser profile. In the user profile this generates a list of assertions which are filteredfrom the events generated by the user and act on a certain resource like a program,per ...