The web before Semantic Web Based on HTML Syntax but without paying attention to Semantics Christmas Salad: People are nuts Spinach, blue with Christmas cheese and nutsdeals, they would buy even a bluespinach if there is a deal Living Social Deal: Mountain Trip. Christmas is the best time to collect nuts in Mountain X
Web 1.0. 2.0. 3.0…….• Not only to access data but create relationships among data • NOT • BUT
Semantic Web• “The Semantic Web is not a separate Web but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation.“ cited by Berners- Lee (2001)Web of data, Linked Web, the Intelligent Web, Web 3.0.
Creator: Tim Berners - Lee• 1994: WWW Geneva Conference• 2001: Scientific American• Director of the World Wide Web Consortium (W3C)
The “syntax” part • Triple URI - Uniform Resource Identifier Triple URIs identify not just Web documents, but also “real- world objects” or “things”HOW???Resource Description Framework (RDF): a framework for representinginformation in the Web.“RDF is a general method to decompose any type of knowledge into small pieces,with some rules about the semantics, or meaning, of those pieces. The point is tohave a method so simple that it can express any fact, and yet structured enoughthat computer applications can do useful things with it”• RDF XML is the standard format for RDF but NOT the only format
The “semantic” part1. Query (SPARQL) : technologies and protocols that canprogrammatically retrieve information from the Web of Data.• RDF set relationships among resources SPARQL queries provide one or more patterns against such relationships.2. Vocabulary or Ontologies (OWL): define the concepts andrelationships used to describe and represent an area of concern• Classify terms, look at possible relationships, and define rules of when to use those terms.3. Inference: generate new relationships based on the data and basedon additional information from vocabulary