Ontology development

• The hard work is to create the ontologies

• • requires a good knowledge of the area to be described
  • some communities have good expertise already (e.g., librarians)
  • OWL is just a tool to formalize ontologies

• Large scale ontologies are often developed in a community process

• Ontologies should be shared and reused

• • can be via the simple namespace mechanisms…
  • …or via explicit inclusions

• Applications can also be developed with very small ontologies, though