Comments on: Is a class the same as its extent?

By: OWL, an ontology language | Ontogenesis

OWL, an ontology language | Ontogenesis — Mon, 16 May 2011 11:59:14 +0000

[…] This article takes the reader on an introductory tour of OWL, with particular attention on the meaning of OWL statements, their entailments, and what reasoners do. Related Knowledge Blog posts include one on ontology components, one on OWL syntaxes, and one on the extent of classes. […]

By: Phillip Lord

Phillip Lord — Wed, 23 Mar 2011 12:52:21 +0000

Thanks for your review James. I’ve marked the article as reviewed.

By: James Malone

James Malone — Fri, 18 Mar 2011 16:25:30 +0000

Thank you for addressing my comments. The article looks good.

By: James Malone

James Malone — Tue, 01 Mar 2011 10:43:41 +0000

An interesting article which usefully points out the perceived differences in definitions that hold for a class in OWL. It is interesting to note that many developers will engineer ontologies with the extent of classes in mind for their model and use instances as a ‘checking’ mechanism to ensure the extent is adequate. In this sense they are using both the extent and the set of individuals to define a class, which I think does not contradict the statements you make here. I would have perhaps liked to have seen a sentence or two at the end explicitly stating your definitions, in conclusion, of what an extent is following your analysis and things that it is/is not with reference to the set of individuals, to reinforce your point.