Ontology

What is an ontology?

In philosophy,

“ontology is the study of being or existence. It seeks to describe or posit the basic categories and relationships of being or existence to define entities and types of entities.”1) Rana, Noman. Small Business - The Art of the Start. Self-Help Publishers, 2009.

In modern computer science and information science basic definitions consider an ontology to be:

“a data model that represents a set of concepts within a domain, and the relationships between those concepts”1)

“an explicit specification of a conceptualization.”2) Gruber, Thomas R. A translation approach to portable ontology specifications. Knowledge acquisition, 5: 199-220, 1993.

“an explicit formal specification of the terms in the domain and relations among them”3) Gruber, Thomas R. A translation approach to portable ontology specifications. Knowledge acquisition, 5: 199-220, 1993. cited by Noy, Natalya F., and Deborah L. Mcguinness. Ontology Development 101: A Guide to Creating Your First Ontology, 2001.

In more details, an ontology can be described as:

a formal explicit description of concepts or classes in a domain of discourse, with

properties of each concept describing various features and attributes of the concept (slots, roles or properties), and

restrictions on concept slots (facets or role restrictions).4) Noy, Natalya F., and Deborah L. Mcguinness. Ontology Development 101: A Guide to Creating Your First Ontology, 2001.

An ontology has the following properties:1)

it is used to reason about the objects in a domain;

specifies the classes of concepts and their relations at a higher level than relevant to the domain;

captures the intrinsic conceptual structure of a domain;

forms the hearth of the knowledge representation within a domain.

Why do we need an ontology?

An ontology can be used to:4)

share common understanding of the structure of information among people or software agents

enable reuse of domain knowledge

make domain assumptions explicit

separate domain knowledge from the operational knowledge

analyze domain knowledge

So how do you create an ontology?

You can follow this brief guide or a more detailed description with examples named Ontology Development 101: A Guide to Creating Your First Ontology.