Individuals
Individuals (instances) are the basic, "ground level" components of an ontology. The individuals in an ontology may include concrete objects such as people, animals, tables, automobiles, molecules, and planets, as well as abstract individuals such as numbers and words (although there are differences of opinion as to whether numbers and words are classes or individuals). Strictly speaking, an ontology need not include any individuals, but one of the general purposes of an ontology is to provide a means of classifying individuals, even if those individuals are not explicitly part of the ontology.
In formal extensional ontologies, only the utterances of words and numbers are considered individuals – the numbers and names themselves are classes. In a 4D ontology, an individual is identified by its spatio-temporal extent. Examples of formal extensional ontologies are ISO 15926 and the model in development by the IDEAS Group.
Read more about this topic: Ontology Components
Famous quotes containing the word individuals:
“Let ... individuals make the most of what God has given them, have their neighbors do the same, and then do all they can to serve each other. There is no use in one man, or one nation, to try to do or be everything. It is a good thing to be dependent on each other for something, it makes us civil and peaceable.”
—Sojourner Truth (c. 1797–1883)
“When posterity judges our actions here it will perhaps see us not as unwilling prisoners but as men who for whatever reason preferred to remain non-contributing individuals on the edge of society.”
—George Lucas (b. 1944)