1. Department of Computer Science Intelligent Information Systems Lab University of Niš 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 The Semantics of Collaborative Tagging Systems Milorad Tosic mbtosic@yahoo.com http://infosys1.elfak.ni.ac.yu

2. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 To build a solid framework for making questions about semantics of collaborative tagging systems. What is that we want to accomplish as our great challenge?  “Web as a Platform” How we would develop scripting applications on the “Web as a Platform”? Goals of the paper

3. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Goals: Wants to bring meaning to the millions of pages of text on the web.  “Web for machines”: Annotate existing information with appropriate metadata such that computers can “understand” rather than just display the data. Opportunity: Work on developing necessary infrastructure that would unleash the power of collective human intelligence scalable to whole humanity. Semantic Web

4. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Challenge:  Do I work on the right problem or I am just working on reinventing the wheel but in different programming language?  Developing applications with high social impact:  Are Semantic Web and Web 2.0 just two sides of the same coin?  Scripting as the most promising approach to development of semantic software intensive systems Scripting and Semantic Web

5. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Three orthogonal dimensions of a scripting language:  Language characteristics (such as weak typing)  System that is programmed by the scripting language  Shell scripting – OS commands  MS VisualBasic – ActiveX and COM  JavaScript - DOM  Application under development Scripting and Semantic Web

6. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Ongoing debate over the concept of resource Why the concept of resource is so important for Semantic Web?  Transferring data is not enough anymore,  We have the need to communicate knowledge Resource is a generic term for anything in the universe of discourse that has identity. Broken link in Google or uncreated page in Wiki? Concept of Resource

7. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 What do we do when we tag?  We are doing some mental work, work on semantics Is our mental process when we tag different then when we search, browse, blog, program or talk over the phone?  No, technological details make the only difference? Mental process of Tagging

8. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 The set of agents, AG={agi| i=1,2,…,n}, that may ever exist in any system under consideration is called an universal space of resources U, also referred to as the universe of discourse.  set of entities AG={agi| i=1,2,…,n}, called agents  each agent in the set carries certain amount of its own local information, agent’s local state, s(agi) Multi-agent interpretation

9. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Set of agents AG={agi| i=1,2,…,n} is closed. Interaction  If agent agi may change local state of some other agent agj, or if agent agj may observe a (certain) change in the state of the agent agi, then we say that agents agi and agj are interacting, and such their setting is called interaction,  ij  agi  agj.  Interaction protocol is initiated between two interacting agents Multi-agent interpretation

10. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Link is knowledge that an agent has about identity of some other agent. The link is knowledge that is sufficient for the agent to initiate an interaction protocol with the linked agent. Tag Cloud (TC) is a tuple TC =(R,L) where R  U is a non empty set of resources contained in an universal space of resources U, also referred to as the universe of discourse, L = {(r,RID(p)) | r  R, p  U} is a set of links, RID (p): R  A is a resource identity function that is mapping from the set of resources to the set of addresses A. Multi-agent interpretation

11. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Tag Cloud System (TCS) is a tuple TCS=(R,L,  ), where TC =(R,L) is a Tag Cloud, and  is a set of collections of resources from U such that each collection C  is defined by the associated membership function mC.  The idea is to have flexibility to being able to introduce different collections with membership functions of different nature, including fuzzy sets Multi-agent interpretation

12. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Collaborative Tagging Prototype

13. 2 nd Workshop on Scripting for the Semantic Web, ESWC2006 4/15/2005 Questions? Thank you for your attention! mbtosic@yahoo.com Department of Computer Science Intelligent Information Systems Lab