I first heard it as “The specification of a Conceptualization”. Looked good to me. I went about life as usual. When someone asked me what an Ontology is, I would simply repeat the very concise definitioin. I got strange looks.
So I went down to investigate. The first entry in a Google Search found this link. Some of my favorites from this list.
“A model of a particular field of knowledge – the concepts and their attributes, as well as the relationships between the concepts. ”
“A partial specification of a conceptual vocabulary to be used for formulating knowledge-level theories about a domain of discourse. The fundamental role of an ontology is to support knowledge sharing and reuse. ”
“The hierarchical structuring of knowledge about things by subcategorising them according to their essential (or at least relevant and/or cognitive) qualities. This is an extension of the previous senses of “ontology” which has become common in discussions about the difficulty of maintaining subject indices. ”
So why is it important? You notice the growth of clustering search engines like Vivisimo and TopGist. “Major web search services like Google and Yahoo are using ontology-based approaches to find and organize content on the Web.” from this article.
At iMorph, we are always looking at ways to organize information for collaboration. The difficulty we face is that the mental model of information is not the same for every member of a collaboratory.
Ontologies and Taxonomies July 2008
“The word ontology has been used to describe artifacts with different degrees of structure. These range from simple taxonomies (such as the Yahoo hierarchy), to metadata schemes (such as the Dublin Core), to logical theories”. This describes a taxonomy as a simpler version of an ontology, so it makes sense to me to add “ontology” as a fifth step on the four levels of controlled vocabulary shown above. If ontologies are a potentially more complex class of taxonomy, then knowledge of taxonomy development can help ontology development, and vice versa.