Ontology Basics

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An ontology is a formal specification of a conceptualization [Gruber, 93, more on ontology by Gruber].

The term is originally borrowed from philosophy, where Ontology (uncountable term with a capital o) is described as a systematic account of existence. In the computer science area, specifically in the AI community, it is considered an engineering artifact, constituted by a specific vocabulary used to describe a certain reality, plus a set of explicit assumptions regarding the intended meaning of the vocabulary words. The assumptions has usually the form of a first order logical theory where vocabulary words appear as unary (concepts) or binary (relations) predicate names. In its simplest form an ontology will describe a hierarchy of concepts, as it gets mores sophisticated suitable axioms are added. [Lassila & McGuinness, 2001]  present an excellent description of this spectrum.

Pragmatically, a common ontology defines the vocabulary with which queries and assertions are exchanged among software agents. Ontological commitments are agreements to use the shared vocabulary in a coherent and consistent manner. The agents sharing a vocabulary need not share a knowledge base; each knows things the other does not, and an agent that commits to an ontology is not required to answer all queries that can be formulated in the shared vocabulary. In short, a commitment to a common ontology is a guarantee of consistency, but not completeness, with respect to queries and assertions using the vocabulary defined in the ontology.

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How can it address our issues?

SwE BOK development approach has to provide support for automated collection and categorization of information.

• Since an ontology subsumes a taxonomy, classification and categorization is integrated with the ontology building process.
• Since an ontology by definition must be a shared, consensual and formal terminology that is used for information sharing and exchange ambiguities are also automatically resolved during the development time.
• They provide a richer environment for agent based software systems. Their formalism allows us to build software that "understands" ontologies and therefore can handle them "intelligently."

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Why Web-enabled?

Internet provides the infrastructure to enable global communication and ontologies provide a shared and common understanding of a domain, their marriage allows for representation of domain knowledge that can be communicated between people and heterogeneous and distributed application systems

We have mentioned before that in order to gain acceptance from the software development community the SwE BOK has to provide immediate benefit to their task at hand.

• Software engineering ontologies deployed on the Internet with sophisticated querying facility will be much more attractive to the software developers then the current SwE BOK implementation that are available only as static text documents.
  
• There has been considerable work already done in the area of intelligent CASE tools to capture and provide task-specific software development knowledge to the software engineers. Our proposed framework builds on those successes, and help them cross the organizational boundary, be globally accessible and applicable to more generic areas.