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Knowledge Management in a Wiki Platform Via Microformats Knowledge Management in a Wiki Platform via Microformats Sergiu Dumitriu and Marta Gˆırdea and Sabin Buraga Faculty of Computer Science, “Alexandru Ioan Cuza” University General Berthelot 16, Ias¸i, Romania {sergiu.dumitriu,marta,busaco}@info.uaic.ro Abstract Knowledge Management The paper presents a conceptual solution and an implementa- In this section, we tackle the problem of knowledge flow tion for acquiring, modeling, publishing, retrieving, reusing in collaborative environments. We refer to the six aspects and maintaining knowledge within XWiki, an open source identified in the Advanced Knowledge Technologies (AKT) collaborative system. We propose a new microformat (hLo- objectives (Shadbolt & O’Hara 2004), and we describe a cation) to denote georeferences (locations). The provided model which makes use of semantic web principles and in- case-studies illustrate the facets of Semantic Web (metadata, tegrates them into collaborative environments, without re- microformats, ontologies) participating to the platform’s en- hancements. quiring, from the contributing authors of the information managed within the platform, any particular effort to intro- duce metainformation or any knowledge of semantic Web Introduction languages. The paper emphasizes the types of metadata we consider relevant in such a collaborative environment, pro- When advancing towards Semantic Web (Berners-Lee, poses a way of expressing such information, and gives an Hendler, & Lassila May 2001; Daconta, Smith, & Obrst example of automatic reasoning based on this structured in- 2003; Shadbolt, Hall, & Berners-Lee 2006), the main obsta- formation (metadata and microformats). cle is the effort of organizing the knowledge (content, meta- data, ontological constructs) made by the content providers. In the current systems, the users must work with certain vo- The Problem cabularies, tagging entities and relations. The purpose of Currently, most online content is created only with the vi- these processes is to make the data comprehensible not only sual result in mind, disregarding any semantic structure of for humans, but also for computers. the (X)HTML source. Table-based layout, images replac- A possible solution is the use of a flexible collaborative ing text, extensive use of presentational tags like <font> platform which helps to transparently organize (meta)data and <center>, make it even harder for Web crawlers to re- for machine-comprehensibility. trieve information, in the same way a human agent perceives Recently, the predominant type of collaborative Web- it. Automatic extraction of the Web documents’ semantics based systems is the wiki (Leuf & Cunningham 2001), is a very difficult task. This is why current search engines which offers premises for creating the knowledge base on are still based on keywords and can not answer simple ques- a certain domain by using Web technologies. A traditional tions1. wiki system provides a Web interface for (collaborative) Web sites should aid this knowledge harvesting by struc- content editing. Main facilities are the simplified syntax, turing information in a semantic manner, in order to make the rollback mechanism, the (possibly) unrestricted access, knowledge available both for humans and computers. Be- several search functions, the support for uploading content. cause it is very unlikely for human agents to semantically or- Wiki platforms are currently used for different purposes, ganize information and to attach metadata, the underlaying such as encyclopedias, software development, project man- Web platform should transparently offer knowledge man- agement, personal knowledge management, content man- agement. agement, collaborative writing, and many others (Schaffert, Gruber, & Westenthaler 2005). AKT identifies six challenges that concern the engineer- To achieve significant knowledge acquisition, a modern ing and management of knowledge: acquiring, modelling, wiki must support user collaborative tools and, more impor- reusing, retrieving, publishing and maintaining knowl- tant, must allow attaching metadata to the concepts and re- edge (Shadbolt & O’Hara 2004). lations established between the involved concepts. 1Several search engines provide answers to a few standard ques- Copyright c 2007, American Association for Artificial Intelli- tions, such as “Population of Japan” or “Pope John Paul II’s birth- gence (www.aaai.org). All rights reserved. day”. 278 Our Approach Reusing Each entity is defined only once and attached to the mostly related document. The information can be glob- In our vision, a non-intrusive knowledge management plat- ally accessed (e.g., the information about a user can be dis- form should have the following approach: played in any page), according to certain permissions (for example, the users can edit a certain document fragment only if they belong to a given group). In order to encourage Acquiring The system should acquire knowledge, and not users to reuse the existing information, the system should formatted text. We noticed that it can be difficult for people provide an easy to use and understand syntax. without education in the field to get used to concepts such as XML. Therefore, asking all users to markup the content they enter in a Website using RDF and OWL would fail. Retrieving Due to rigorous manner of structuring content, The fundamental concept of semantic Web is the triple (en- it should be easy to retrieve pieces of information by per- tity has property with value). The common perception is that forming different queries. Supplementary, the system will the entity (an information fragment), although it belongs to be able to automatically aggregate, retrieve, and extract in- a structured class, is a region of an on-line document, identi- formation on the basis of metadata and inter-object relations. fied by an URI. Storing the data only as formatted text causes For example, ad-hoc groups of users (including the relations the loss of the semantic relations between information frag- of collaboration between them) can be obtained from certain ments. For example, in a “Call for Papers” document it is metadata regarding their interests. difficult to markup the relations between the event and its location or the involved persons (organizers, invited lectur- Publishing With the help of well-known metadata stan- ers, regular participants). dards (such as DCMI – Dublin Core Metadata Initiative) and A better solution would be to store the concepts only as microformats (Khare & C¸ elik 2006) – e.g., hCard, hResume, structured information, and display their properties/relations XFN, and our proposal hLocation (see below), information in the document as needed. Acquiring such structured infor- can be properly organized for both human and computer ac- mation can be performed using (X)HTML forms. Each form cess and can be rendered according to the user needs and field identifies the entity and the property, and the user must preferences. For example, the news regarding the activities assign the proper value. of a research group can be distributed and published in many Another way of information gathering involves obtain- forms by using hCalendar and RSS/Atom feeds. For a better ing selected (semi)structured data from external sources semantic (re)use, the stored knowledge can be exported to (RSS/Atom feeds, Web services, CGI scripts, RDF stores, RDF/OWL documents (all internal classes have correspond- databases). ing OWL classes and the individuals can be exported as RDF Classes can also be defined on the basis of triple model. triples). Each class property is defined starting from standard types (i.e., XML Schema datatypes: string, number, boolean etc., Maintaining Because our approach is a wiki-like one, the and reference), and form fields are used to adapt it by defin- knowledge can be easily maintained in a collaborative man- ing the property name and restricting the range. ner. The users can annotate, review, re-edit, and delete frag- ments of information as needed. Modelling Although each piece of information should be Conceptual Model for a Collaborative semantically modelled, this approach seems almost impos- sible in practice2. Our point of view is to rigorously express Wiki-like System certain important information following the object-oriented Entities and Relations paradigm. As it is not feasible to model any information, we must iden- To properly model the knowledge, some steps must be tify and define the most important concepts regarding a col- performed (Daconta, Smith, & Obrst 2003): laborative platform. General concepts for all wiki systems are: users (individuals and groups), documents (composed 1. the classes needed to be used are identified; by content and metadata), events, and places. For publish- 2. the properties are defined; ing each of them, we make use of the existing metadata languages or we investigate the possibility of defining new 3. the information regarding the individuals (class instances) ones. is filled in via collaborative mechanisms by the involved users. Users This class denotes the concept of user and should In contrast with closed-world approach (where all classes describe the following attributes: name, address(es), affil- and properties are a-priori defined), XWiki permits adding iation, interests, location, age, contact information. For and modifying classes and the respective properties at any specific-purpose collaborative systems, this class can be re- moment. fined in order to better reflect the user concept (e.g., an e-learning wiki can use Student class derived
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