The SIOC Project: Semantically-Interlinked Online Communities
Uldis Boj¯ars and Alexandre Passant and John G. Breslin and Stefan Decker Digital Enterprise Research Institute,
National University of Ireland, Galway, Ireland.
Email: [uldis.bojars,alexandre.passant,john.breslin,stefan.decker]@deri.org
Abstract—The SIOC project is aimed at expressing information about the structure and content of online community sites and at enabling interoperability on the Social Web using Semantic Web technologies. In this paper we briefly describe the SIOC project, introduce the SIOC Core ontology and its modules, and discuss some SIOC-based applications in terms of human and agent communication.
I. INTRODUCTION
While new paradigms, tools and web services introduced by the Social Web (such as blogs, wikis, tagging practices) are now widely accepted in both public and scientific com- munities, these tools generally act as independent data silos;
hence, interoperability between applications is a complex issue. The SIOC project1 aims at solving this by providing a comprehensive data model (as well as related tools and applications) based on Semantic Web technologies [1] in order to represent online communities and their activities in an homogenous way.
The SIOC project consists of two main parts:
• The SIOC Ontology, composed of a Core ontology and different modules;
• A set of applications, for both producing and consuming SIOC data, constantly evolving based on the user needs and implementations.
II. THESIOC ONTOLOGY
The SIOC Ontology is composed of a Core ontology and a set of modules, focusing on the ease of integration of SIOC in existing applications by Web developers. With an emphasis on standard Semantic Web technologies since its beginning, the whole ontology has been designed using RDF(S)/OWL.
A comprehensive overview of the SIOC ontology is provided in [2].
A. SIOC Core Ontology
Main classes and properties in the SIOC ontology2 are shown in Figure 1. While relatively small and simple, this model is yet powerful enough to represent the content pro- duced and exchanged within online communities. For instance, aForumrepresents a space in which discussion happen (not necessarily a bulletin board, in spite of its name, but for example as a weblog), and contains differentPosts, written
1http://sioc-project.org
2http://rdfs.org/sioc/spec
by Users. The following example then describes that Alice has created a post in a particular forum (i.e. an area of discussion) and that Bob replied to it — as follows (using the N3 notation - prefixes omitted). In order to represent more abstract containers (such as a personal information space), more general ContainerandSpaceclasses can be used.
:post a sioc:Post ;
sioc:has_creator :alice ; sioc:has_container :forum ; sioc:has_reply :reply . :forum a sioc:Forum . :reply a sioc:Post ;
sioc:has_creator :bob . :alice a sioc:User . :bob a sioc:User .
Fig. 1. Main classes and properties in the SIOC ontology.
Other properties and classes exist in the ontology, for instance properties to represent previous and next versions of an item, which can be used when representing Wikis.
It is worth noticing that each sioc:User is actually related to the Agent class (from the FOAF3 — Friend Of A Friend [3] — ontology), and that sioc:User can be consequently associated with both software agents and human users. Hence, SIOC can be used to represent communication between bots on the Social Web (e.g. on IRC using the
3http://foaf-project.org
SIOC-IRClog project4) and then enable a machine-readable description of communities of agents interacting together on social websites. Moreover, another link between FOAF and SIOC is that the social networking aspect can be represented using FOAF (by foaf:knows), while SIOC can be used to represent aspects of relationships inside the community, e.g.
a user following another (on microblogging services) can be expressed by thesioc:followsproperty.
B. SIOC Modules
Several SIOC modules have been defined to extend the available terms and to avoid making the SIOC Core Ontology too complex and unreadable. SIOC has 4 ontology modules:
Access, Argumentation, Services and Types5.
• the Access module defines simple classes and properties regarding the notions of Role and Permission to represent access rights and permissions in online communities websites;
• the Argument module defines classes and properties to represent simple argumentative discussions in online communities websites.
• the Services module defines classes and properties to reprsent Web services related to online communities (e.g.
API endpoint and return format, etc.);
• the Types module defines advanced content-types to be used when defining user-generated content from online- communities. For instance, it includes classes such as sioct:BlogPostor sioct:Wiki that respectively subclass thesioc:Postandsioc:Forumclasses from the Core Ontology;
In addition, one of the recent development of SIOC is a module defining alignments between SIOC and the SWAN
— Semantic Web Applications in Neuromedicine — ontology [4]6, providing a complete model for fine-grained argumenta- tive discussions in online scientific communities.
III. STATUS ANDUPDATE OFSIOC
Since the goal of SIOC is to provide interoperability be- tween communities on the Social Web, one way to evaluate its success is to consider its uptake on the Web. To illustrate the amount of SIOC data on the Web, according to the PingTheSemanticWeb (PTSW) service7 on June 2009 there were 132’475 URIs which contain data described using the SIOC ontology8.
In addition to the uptake in terms of number of documents, SIOC is now widely accepted as a core ontology to describe Social Web communities using Semantic Web technologies, alongside with FOAF. Hence, the use of SIOC is suggested by the Yahoo! SearchMonkey developer documentation9 (SIOC
4http://irc.sioc-project.org/about.html
5Information about SIOC modules: http://rdfs.org/sioc/spec/#sec-modules
6http://rdfs.org/sioc/swan
7http://pingthesemanticweb.com
8The full amount of SIOC information on the Web is larger than described here as PTSW indexes only a part of available RDF data.
9http://developer.yahoo.com/searchmonkey/smguide/profile vocab.html
data being indexed by SearchMonkey to improve presentation of search results) and by various best practices documents describing data publishing on the Semantic Web such as [5].
Various SIOC-enabled applications have been created10, forming a food-chain (Figure 2) that includes data exporters for Web 2.0 platforms and services (e.g.Drupal11, WordPress, Flickr, etc.), tools for indexing of distributed data, and browser and visualization applications, allowing users to consume SIOC data from various sources in an integrated way.
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SIOC ontology is an open data format for describing structure and content of social media sites in RDF.
SIOC follows best practices of the Semantic Web by reusing existing ontologies: Dublin Core, FOAF, SKOS.
Modularised design allows us to keep the SIOC Core ontology simple and easy to understand while ensuring extensibility.
W3C Member Submission of the SIOC Ontology published in July 2007.
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Applications with Native Storage of SIOC Data Bypassing Apps by
Directly Mapping RDBMS to SIOC Add-Ons and Fns for Exporting SIOC from Existing Apps SIOC from Semi- Structured Data or Queryable APIs
SIOC Crawlers and Aggregate Storage of Data Indexers of SIOC Instances w/o Full Storage
RDF Browsers and Other Custom
SIOC Explorers SIOC Detectors and Clipping Applications
Reuse and Import for Data Portability Requirements Graphical Viz of Derived SIOC
Networks C((7%$4./&
(2%@II)/0.'/(&1 has_host
has_reply
has_container
User Role
has_function
Usergroup
has_member has_scope
has_creator has_parent
Container Space
has_space
Item
has_container
subClassOf subClassOf subClassOf
Forum Site
Post
Topic
topic
Fig. 2. The SIOC food-chain
IV. CONCLUSION
In this paper, we briefly introduced the SIOC project, its goals and means as well as uptake and services overview. In particular, in the context of multi-agent systems and online communities, an already active fields for several years if we consider for instance [6], the SIOC ontology could be used to express in a unified way information about activities of both humans and agents interacting in these communities.
ACKNOWLEDGEMENTS
The work presented in this paper has been funded in part by Science Foundation Ireland under Grant No. SFI/08/CE/I1380 (L´ıon-2).
REFERENCES
[1] T. Berners-Lee, J. A. Hendler, and O. Lassila, “The Semantic Web,”
Scientific American, vol. 284, no. 5, pp. 34–43, 2001.
[2] U. Boj¯ars, J. G. Breslin, V. Peristeras, G. Tummarello, and S. Decker,
“Interlinking the Social Web with Semantics,”IEEE Intelligent Systems, vol. 23, no. 3, pp. 29–40, May/June 2008.
[3] D. Brickley and L. Miller, “FOAF Vocabulary Specification,”
FOAF Project, Namespace Document 2 Sept 2004, 2004, http://xmlns.com/foaf/0.1/. [Online]. Available: http://xmlns.com/foaf/0.1/
[4] P. Ciccarese, E. Wu, G. Wong, M. Ocana, J. Kinoshita, A. Ruttenberg, and T. Clark, “The SWAN biomedical discourse ontology,”Journal of Biomedical Informatics, vol. 41, no. 5, pp. 739–751, 2008.
[5] C. Bizer, R. Cyganiak, and T. Heath, “How to Publish Linked Data on the Web,” Tech. Rep., 2007, http://www4.wiwiss.fu-berlin.de/bizer/pub/
LinkedDataTutorial/.
[6] F. Gandon and R. Dieng-Kuntz, “Distributed Artificial Intelligence for Distributed Corporate Knowledge Management,” in CIA 2002 - 6th Cooperative Information Agents - Intelligent Agents for the Internet and Web September. Springer LNAI 2446, pp. 202–217.
10http://rdfs.org/sioc/applications/
11http://drupal.org/project/sioc
