Chapter 1 - What Is the Semantic Web?

Abstract

The Web today is something of an unruly place, with a wide variety of different sources, organizations, and styles of information. Effective and creative use of search engines is something of a craft; efforts to make order from this include community efforts like social bookmarking and community encyclopedias to automated methods like statistical correlations and fuzzy similarity matches. For the Semantic Web, which operates at the finer level of individual statements about data, the situation is even wilder. With a human in the loop, contradictions and inconsistencies in the document Web can be dealt with by the process of human observation and application of common sense. If the document Web is unruly, then surely the Semantic Web is a jungle—a rich mass of interconnected information, without any roadmap, index, or guidance. How such a mess can become something useful is the challenge that faces the working ontologist. Their medium is the distributed web of data; their tools are the Semantic Web languages RDF (Resource Description Framework), RDFS (RDF Schema), and OWL (Web Ontology Language). Their craft is to make sensible, usable, and durable information resources from this medium. The main idea of the Semantic Web is to support a distributed Web at the level of the data rather than at the level of the presentation. Instead of having one webpage point to another, one data item can point to another, using global references called uniform resource identifiers (URIs). The Web infrastructure provides a data model whereby information about a single entity can be distributed over the Web.