Using Existing Ontologies

Just as with other types of controlled vocabulariesA managed list of terms. In the context of vocabularies, management typically includes careful selection of terms, maintenance of terms over time (i.e. addition, deprecation, modification), and presentation of the vocabulary in an accessible format. Related Guide, there are many opportunities for communities to use the same ontologiesA type of relational controlled vocabulary, which provides for categories, relationships, rules and axioms among metadata elements. Typically a hierarchy of classes and terms, an ontology is a machine-readable way of relating metadata terminology. Related Guide. This can save time and resources and provide a common way to share data among different members of a community.

There are several toolsets that can facilitate your work with ontologies. First, a major hurdle to the adoption of this technology is a simple method by which to discover commonly used ontologies. Search engines and community-run registries and repositories—several of which are listed in the next section—can help.

However, even under the best of circumstances, a pre-existing ontology may need to be adapted for use in particular cases. Fortunately, RDFResource Description Framework and OWLWeb Ontology Language provide good mechanisms for extending individual ontologies, allowing them to be modified while still retaining their original meanings and relationshipsConnections between metadata terms within a vocabulary. These relationships can connect terms by scope, provenance, or other well-defined criteria..

This section of the guide covers methods for finding ontologies, citing their terms and resources, and extending existing ontologies to work for your needs.