The future of the Web: Semantic Web 9/30/2004 Xiangming Mu

What is Semantic Web "The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation." -- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American, May 2001The Semantic Web

What is semantic web (cont’) The Semantic Web allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF), which integrates a variety of applications using XML for syntax and URIs for naming.RDF –XML: eXtensible Markup Language have data on the web defined and linked in a way that it can be used by machines not just for display purposes, but for automation, integration and reuse of data across various applications.

Why Semantic Web? A case study Harper’s Magazine online

RDF The Resource Description Framework (RDF) –is a language for representing information about resources in the World Wide Web. –Particularly intended for representing metadata about Web resources, such as the title, author, and modification date of a Web page, copyright and licensing information about a Web document –Also represent information about things that can be identified on the Web, even when they cannot be directly retrieved on the Web. e.g., information about specifications, prices, and availability. –is intended for situations in which this information needs to be processed by applications, rather than being only displayed to people. –provides a common framework for expressing this information so it can be exchanged between applications without loss of meaning.

–based on the idea of identifying things using Web identifiers (called Uniform Resource Identifiers, or URIs), –and describing resources in terms of simple properties and property values. –RDF Primer from W3CRDF Primer RDF (cont’)

An example of RDF There is a Person identified by whose name is Eric Miller, whose address is and whose title is Dr. <rdf:RDF xmlns:rdf=" xmlns:contact=" Eric Miller Dr.

Ontology Ontology: –defines the terms used to describe and represent an area of knowledge. –are used by people, databases, and applications that need to share domain information a domain is just a specific subject area or area of knowledge, like medicine, tool manufacturing, real estate, automobile repair, financial management, etc. –include computer-usable definitions of basic concepts in the domain and the relationships among them. They encode knowledge in a domain and also knowledge that spans domains. In this way, they make that knowledge reusable.

OWL OWL: Web Ontology Language –designed to process the content of information instead of just presenting information to humans –supported by XML, RDF, and RDF Schema (RDF-S) and provides additional vocabulary along with a formal semantics –has three increasingly-expressive sublanguages: OWL Lite OWL DL OWL Full –An overview of OWL from W3Coverview