According to Tom Gruber, former research associate at the Stanford Knowledge Systems Lab, the term "ontology" seems to generate a lot of controversy in discussions about Artificial Intelligence. It has a long history in philosophy, in which it refers to the subject of existence.

Many use the term ontology to mean a specification of a conceptualization. That is, an ontology is a description of the concepts and relationships that can exist for an agent or a community of agents. This definition is consistent with the usage of ontology as set-of-concept-definitions, but more general...What is important is what an ontology is for. Many design ontologies for the purpose of enabling knowledge sharing and reuse. Ying Ding, another information scientist who has published several articles on ontologies further states: "An ontology is an important emerging discipline that has the huge potential to improve information organization, management and understanding. It has a crucial role to play in enabling content-based access, interoperability, communications, and providing qualitatively new levels of services on the next wave of web transformation in the form of the semantic Web."

Unlike most MD-WG sessions, we plan to engage in an open and introductory discussion to explore ontologies. We hope that in the course of our discussions, many of you will be able to answer these questions:

• What is an ontology?
• What are they used for?
• How can libraries use ontologies?
• What are the differences and similarities among ontologies, thesauri, and taxonomies?

In the course of the discussion, Jon Corson-Rikert (Program Analyst, Albert Mann Library) will demonstrate some of his preliminary work applying Lagoze and Hunter's ABC Ontology to Mann Library's Agricultural Heritage Project.

If you are not familiar with ontologies, we recommend that you take a look at the links below, which discuss:

• CONTROLLED VOCABULARY (organized list of words and phrases, or notation systems)
• ONTOLOGY (specification of a conceptualization)
• TAXONOMY (classified collection of elements)
• THESAURUS (vocabulary of a controlled indexing language, formally organized so that the a priori relationships between concepts (for example as "broader" and "narrower") are made explicit)

Jon Corson-Rikert led the group in a discussion of "Ontologies: What, Why, and How?"; Jon illustrated the concepts he described by demonstrating the work he has done on the Cooperative Crop Research Program site (http://mcknight.ccrp.cornell.edu) and on a Prototype Agriculture Heritage Web Site in which Jon has applied the principles of Lagoze and Hunter's ABC Ontology. Anyone interested in learning more about Jon's design for the Agricultural Heritage site can contact Jon directly (jc55@cornell.edu)