A User Profile Ontology For Situation-Aware Social Networking Johann Stan1 and Elod¨ Egyed-Zsigmond2 and Adrien Joly3 and Pierre Maret4 Abstract. Today, more and more people possess mobile devices. • Another key issue is to reduce the human intervention: situation This enables them to have access to a wide range of services, but changes need to be detected in real-time and a corresponding set also to be contacted anytime, anywhere, which can cause discomfort. of user preferences activated for each situation. People should have full control on who can reach them and how, de- pending on their current situation: when at work, a friend’s call or A summary of these conclusions could be that there is a neces- during a family dinner a call related to work is not always appreci- sity to have a straightforward relationship concerning reachability ated. Furthermore, situation changes need to be detected in real-time, between current situations and the social network of the user. This since preferences change a lot. We present in this paper an ontology- relationship must be a real-time adaptable interface between the two based user profile model, that allows users to have a situation-aware entities. Similar to the advantages of a recommendation system [15], social network, by controlling how reachable they are for specific such a mechanism would reduce organizational activity and would categories of people in a given situation. optimize productivity, since from the user’s point of view, having a full control of who can interrupt him and how in a given situation would be of real help to perform the current activity with less stress. 1 Introduction Inspired by existing and recently published semantical user pro- With the emergence of mobile phones as a daily companion, people files, can be reached almost everywhere by everybody: a friend might call during a project meeting, or a commercial advert can arrive during a • We describe a user profile that allows to efficiently characterize the family dinner. Such situations can cause major discomfort. With the current situation of the user and to express social-network related popular instant messaging software Yahoo Messenger, the user can reachability preferences in situational sub-profiles define his status for a given contact or group of contacts, using the • We explain how this model will detect situation changes in real- stealth settings, which allows him to choose for whom he is reach- time and will allow the user to have a full control of his presence able. This feature is extremely useful, but requires manual settings in the social network each time a change occurs. When one has a big social network, this This paper is organized as follows: after reviewing the existing user can be even more time consuming than an interruption during the task profile models in Section 2, Section 3 and Section 4 present in detail itself. We consider the following scenario to illustrate this problem: our approach. Conclusions and highlights of future work are given in John Smith is a research engineer. He is currently preparing a the final Section. presentation for an important workshop, due in 2 days. Since this is a professional situation for him, he only wants office colleagues and some important family members -wife, babysitter- to be able to 2 Related Work interrupt him directly (a phone call). Friends or other people should not contact him in a way that would require immediate answer. After Recent developments in the field of the semantic web enable a new work, John becomes less busy, so close friends can also contact him. realm of applications. Semantic web made it possible to have the However, he would be disturbed and annoyed if some work-related necessary tools to handle computer-understandable semantics. These call interrupted him during the family dinner. When John is going to tools, generally evolving from XML are used to enrich the descrip- work with the train, anyone can contact him by any means. tion of web-pages, giving a deeper understanding of the relations Based on this example, we can draw several conclusions regarding between the concepts. OWL (Web Ontology Language) [3], RDF social behavior: (Resource Description Framework) [1] are some of the most widely used representations. The advantage of these languages is that they • Situations often change, varying from professional to private, and are machine readable and strongly related to Description Logics. A for each situation, there is the necessity to have full control of how state-of-the art on this subject can be found in [6]. different categories of people in our social network can contact us: The RDF language makes statements about resources in the form friends, family, office colleagues, the babysitter, and also of how of triples: (subject, predicate, object). The subject denotes the re- they can do it: by a phone call, an SMS, instant messaging or just source and the predicate denotes the relationship between the subject by writing an e-mail. and the object, which can be another resource or a literal. The OWL language is built on top of RDF, offering a larger vocabulary and 1 Alcatel-Lucent Bell Labs, email: [email protected] 2 LIRIS CNRS, Lyon, France, email: [email protected] stronger syntax. 3 Alcatel-Lucent Bell Labs, France, email: [email protected] FOAF (Friend-of-a-Friend) [7] is an ontology-based RDF vocabu- 4 LIRIS CNRS, Lyon, France, email: [email protected] lary to describe users profiles, friends, affiliations, creations etc. The aim of FOAF is that of a completely decentralized machine-readable UPOS (User-Profile Ontology with Situation-Dependent Prefer- social network that is based on personal profiles. The profile contains ences Support) [17] is part of the Spice project [2]. It is prob- mostly static data, like personal information, work history, links to ably the newest user profile ontology, addressing both static and contacts and services. context-aware aspects. This ontology, defined in OWL, allows cre- In their work, Carmagnola et al. [8] investigate how tagging allows ating situation-dependent sub-profiles. A user has a profile and a to infer data about user preferences or interests. Tagging is the pro- context (location or activity) associated. The notion of condition is cess where users label or annotate different resources (web-pages for defined, which includes a user, an operator and a context-value. For example) with the objective to share, organize or diffuse them. The example, a condition can be: ”if the context of user Bob equals the way users employ tags might give an insight on different issues like MyOffice location...”. According to this condition, a corresponding how interested they are in the given resource, whereas the type of sub profile can be applied that contains all personalization indica- tags used (many synonyms for example) can infer subjective details tions for services (e.g. not to use sms). This approach was inspired like the level of creativity. by the ETSI human factors group, which defined guidelines for de- Von Hessling et al. [19] propose a model where semantic user pro- signing context-aware user profiles. The most important guideline is files are used in a peer-to-peer mobile environment. The user profile to structure the profile into sub-profiles, each containing user prefer- is relatively simple, consisting simply of the union of interests and ences that correspond to a specific situation, as seen in the previous disinterests. A common domain ontology for concepts in both ser- example. vices and profile description is used to operate the matching with a Existing user model approaches allow to specify a great variety reasoner. What is interesting in this model is the fact that the system of static concepts, like personal data, interests, preferences, but they is completely peer-to-peer (profiles are stored on the mobile device), do not allow sufficient expressivity for real-time situation changes. allowing a better privacy. [18] considers dynamic aspects, but this is reduced to the logging of V. Mendis [12] argues that techniques like RDF and OWL together the user activity enriched with context. Tagging user actions could with ontologies are the key elements in the development of the next be helpful in the identification of the users activity. However this re- generation user profiles. The User Profile Ontology grew out from a quires content analysis of interactions (subject of a mail, voice anal- quite simple model containing semantic contact information encoded ysis of a phone call), which has technical limitations and presents in the RDF language. The proposed ontology is structured in three some privacy concerns. We propose a model based on UPOS (which parts: Person Ontology (containing classes relevant only to the user), integrates static and dynamic concepts in a single term) to represent Organization Ontology (containing business oriented information) the current situation of the user. The next section shows how our and a Common Ontology (containing information relevant to both model extends the UPOSs by considering conjunction of context di- persons and organizations), Personal information (e.g. e-mail, tele- mensions in order to better identify in real-time the situation of users. phone, Instant Messaging identifier, physical addresses) is uniquely identified by a GenericContactIdentifier class. Social interactions in- herit properties from an Event class. These interactions are classified 3 Definitions into voice, text, real-time, online communications. The address book Researchers attempted to define context in various ways, mostly us- of the user is stored into the class ContactGroup. ing terms like location, surrounding people and environmental data, Golemati et al. [11] present an application-independent user pro- like temperature, period of the day and time.