Ontology: An Introduction

Video: How to Build an Ontology
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Philosophical Ontology

Ontology as a branch of philosophy is the science of what is, of the kinds and structures of the objects, properties and relations in every area of reality. Ontology in this sense is often used in such a way as to be synonymous with metaphysics. In simple terms it seeks the classification of entities. Each scientific field will of course have its own preferred ontology, defined by the fields vocabulary and by the canonical formulations of its theories. Traditional (philosophical) ontologists have tended to model themselves on these scientific ontologies, either by producing theories which are like scientific theories but radically more general than these, or by producing theories which represent a regimentation of scientific theories or a clarification of their foundations. Philosophical ontologists have more recently begun to concern themselves not only with the world as this is studied by the sciences, but also with domains of practical activity such as law, medicine, engineering, commerce. They seek to apply the tools of philosophical ontology in order to solve problems which arise in these domains.

Ontology and Information Systems

In the field of information processing there arises what we might call the Tower of Babel problem. Different groups of data-gatherers have their own idiosyncratic terms and concepts in terms of which they represent the information they receive. When the attempt is made to put this information together, methods must be found to resolve terminological and conceptual incompatibilities. Initially, such incompatibilities were resolved on a case-by-case basis. Gradually, however, it was realized that the provision, once and for all, of a common backbone taxonomy of relevant entities of an application domain would provide significant advantages over the case-by-case resolution of incompatibilities. This common backbone taxonomy is referred to by information scientists as an ontology. What is the relationship between these two uses of this term?

Preprint version of chapter Ontology,  in L. Floridi (ed.), Blackwell Guide to the Philosophy of Computing and Information, Oxford: Blackwell, 2003, 155-166.

Longer draft

Terminology for Ontology Development

Buffalo Ontology Site

Training Course: An Introduction to Biomedical Ontology in Eight Lectures (Streaming Video)