Ontology Summit 2007 Communiqué version 1.0.0 / 2007.04.24

NIST, Gaithersburg, Maryland, USA. April 24, 2007

editors:  OlivierBodenreider (NLM) & FrankOlken (NSF, LBNL)   
Under the appellation of "ontology" are found many different types of artifacts created and used in different communities to represent entities and their relationships for purposes including annotating datasets, supporting natural language understanding, integrating information sources, semantic interoperability and to serve as a background knowledge in various applications.

The Ontology Summit 2007 "Ontology, Taxonomy, Folksonomy: Understanding the Distinctions," co-organized by NIST and Ontolog Forum and co-sponsored by some 50 institutions, is an attempt to bring together various communities (computer scientists, information scientists, philosophers, domain experts) having a different understanding of what is an ontology, and to foster dialog and cooperation among these communities.

In practice, the name ontology covers a spectrum of useful artifacts, from formal upper-level ontologies expressed in first order logic (e.g., Basic Formal Ontology (BFO) and DOLCE) to the simple lists of user-defined keywords used, for example, to annotate resources on the Web. The latter are called "folksonomies" and play an important role in the Web 2.0. In between the two extremities of the ontology spectrum are taxonomies and controlled vocabularies (e.g., MeSH), often used for information indexing and retrieval, and whose organization is mostly hierarchical. Finally, there are ontologies which represent not only subsumption , but also other kinds of relationships among entities (e.g., functional, physical), often based on formalisms such as frames or description logics. Examples of such ontologies in the biomedical domain include the Foundational Model of Anatomy, SNOMED CT and the NCI Thesaurus.

The goal of the Ontology Summit is not to establish a definitive definition of the word "ontology", which has proved extremely challenging due to the diversity of artifacts it can refer to. Analogously, the goal is not to organize ontologies along any particular single dimension either. Rather, we propose to identify a limited number of key dimensions along which ontologies can be characterized and to provide operational definitions for these dimensions. The relative position of ontologies in the space defined by these dimensions, the "Framework", is indicative of the similarities and differences between these ontologies. The Framework has been applied to the characterization of a dozen ontologies, whose descriptions were collected through a survey.

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