Lecture Tuesday 05 April 2005

Formal characteristics of formal ontologies

Think ER diagrams!

Information systems need some sort of data dictionary

Extensibility (http://www-2.cs.cmu.edu/People/clamen/OODBMS/Manifesto/htManifesto/node10.html)

Ontologies
Definition with a flexibile set of attributes makes it better able to link up with other representation (more available for crosswalks)

Two ontologies may be the same but the purpose of their implementations may be different, thus foiling efforts to establish crosswalks

"In short, a commitment to a common ontology is a guarantee of consistency, but not completeness, with respect to queries and assertions using the vocabulary defined in the ontology." (*)

WordNet - how do I do word-sense disambiguation


Difference between an ontology and a thesaurus
thesaurus: nodes are words
ontology: starting with concepts & track the concepts