The W3C Web Ontology Working Group has published an initial working draft document outlining requirements for the Ontology Web Language (OWL) 1.0 specification. The draft document "specifies usage scenarios, goals and requirements for a web ontology language. Automated tools can use common sets of terms called ontologies to power services such as more accurate Web search, intelligent software agents, and knowledge management." An 'ontology' in terms of the WG charter "defines the terms used to describe and represent an area of knowledge. Ontologies are used by people, databases, and applications that need to share domain information, where a domain is just a specific subject area or area of knowledge, like medicine, tool manufacturing, real estate, automobile repair, financial management, etc. Ontologies include computer-usable definitions of basic concepts in the domain and the relationships among them... An ontology formally defines a common set of terms that are used to describe and represent a domain. The WD specification motivates the need for a Web ontology language by describing six use cases. Some of these use cases are based on efforts currently underway in industry and academia, others demonstrate more long-term possibilities. The use cases are followed by design goals that describe high-level objectives and guidelines for the development of the language. These design goals will be considered when evaluating proposed features."

Bibliographic information: Requirements for a Web Ontology Language. W3C Working Draft 07-March-2002. Edited by Jeff Heflin (Lehigh University), Raphael Volz (FZI), and Jonathan Dale (Fujitsu). Version URL: http://www.w3.org/TR/2002/WD-webont-req-20020307/. Latest version URL: http://www.w3.org/TR/webont-req/.

From the WD Introduction:

The Semantic Web is a vision for the future of the Web in which information is given explicit meaning, making it easier for machines to automatically process and integrate information available on the Web. The Semantic Web will build on XML's ability to define customized tagging schemes and RDF's flexible approach to representing data. The next element required for the Semantic Web is a Web ontology language which can formally describe the semantics of classes and properties used in web documents. In order for machines to perform useful reasoning tasks on these documents, the language must go beyond the basic semantics of RDF Schema. This document will enumerate the current requirements of such a language. It is expected that future languages will extend this one, adding, among other things, greater logical capabilities and the ability to establish trust on the Semantic Web.

This document motivates the need for a Web ontology language by describing six use cases. Some of these use cases are based on efforts currently underway in industry and academia, others demonstrate more long-term possibilities. The use cases are followed by design goals that describe high-level objectives and guidelines for the development of the language. These design goals will be considered when evaluating proposed features. The section on Requirements presents a set of features that should be in the language and gives motivations for those features. The Objectives section describes a list of features that might be useful for many use cases but may not necessarily be addressed by the working group.

The Web Ontology Working Group charter tasks the group to produce this more expressive semantics and to specify mechanisms by which the language can provide "more complex relationships between entities including: means to limit the properties of classes with respect to number and type, means to infer that items with various properties are members of a particular class, a well-defined model of property inheritance, and similar semantic extensions to the base languages. A first draft of the detailed specification for a Web Ontology language will be made available sometime after this requirements document has been posted for public review. The specification will be developed largely by looking at: (1) the design goals and requirements that are contained in this document; (2) review comments on this document from public feedback, invited experts and working group members; (3) specifications of or proposals for languages that meet many of these requirements.

Excerpts from the six use cases:

• Web portal: "an ontology can provide an expressive terminology for describing content, and inferences sanctioned by the ontology can be used to improve the quality of search on the portal." Like OntoWeb.
• Multimedia collections: "ontologies can be used to provide semantic annotations for collections of images, audio, or other non-textual objects; these annotations can support both indexing and search"
• Corporate web site management: "large corporations have press releases, product offerings and case studies, corporate procedures, internal product briefings and comparisons, white papers, and process descriptions; ontologies can be used to index these documents"
• Design documentation: "for a large body of engineering documentation, [...] ontologies can be used to build an information model which allows the exploration of the information space in terms of the items which are represented, the associations between the items, the properties of the items, and the links to documentation which describes and defines them"
• Intelligent agents: "domain ontologies can be used to provide agents with the capability to understand and integrate diverse information resources." Like Agentcities.
• Ubiquitous computing: "where small, handheld, wireless computing devices require network architectures to support automatic, ad hoc configuration; tasks involved in the utilization of services involve discovery, contracting, and composition..."