An Ontology is “An explicit formal specification of how to represent the objects, concepts, and other entities that are assumed to exist in some area of interest and the relationships that hold among them.” Source: DLI UIUC Glossary, http://dli.grainger.uiuc.edu/glossary.htm. Classes, hierarchies, and relationships among classes, inheritance of properties are all of interest in the construction of an ontology. The ontology specification is usually written in a formal language such as First Order Predicate Logic. The major difference between a bibliographic classification scheme and an ontology (that is a knowledge classification scheme) is that ontologies are usually computationally enforced. In this section information about ontologies is mixed in with a sample ontology editing tool, an ontology library, and an ontology.

Type of Resource: Interactive
Author: Parallel Understanding Systems Group, University of Maryland
Title: Semantic Search: The SHOE Search Engine
Location/Identifier: URL: http://www.cs.umd.edu/projects/plus/SHOE/search/
Subject: Search engines
Keyword: Ontologies,SHOE
Description: SHOE is a small extension to HTML which allows web page authors to annotate their web documents with machine-readable knowledge. SHOE uses XML-like tags and advanced artificial intelligence technology to make keyword based search engines on the web possible.
Rights:
Copyright: Unknown
Access: Freely available.
Date of creation and last modification: Unknown
Format of Resource: text/html
Educational Level: Metadata Architects

Type of Resource: Website
Author: Protege
Title: Protege Ontologies Library
Location/Identifier: URL: http://protege.stanford.edu/ontologies/ontologies.html
Subject: Ontology
Keyword:
Description: Protege is an ontology editor; this website maintained by Protege lists the availability of ontologies for 1) Biological processes, 2) Dublin Core, 3) Gene ontology, 4) Science Ontology, 5) Geographic information metadata, and more. There is also a link to a related site, OWL Ontology Library.
Rights:
Copyright: Unknown
Access: Freely available.
Date of creation and last modification: 2004-00-00
Format of Resource: text/html
Educational Level: Metadata Architects

Type of Resource: Website
Author: Web Ontology Working Group
Title: Web Ontology Working Group
Location/Identifier: URL:http://www.w3.org/2004/OWL/
Subject: Ontology
Keyword:
Description: This working group works with OWL. OWL is a Web Ontology language. Where earlier languages have been used to develop tools and ontologies for specific user communities (particularly in the sciences and in company-specific e-commerce applications), they were not defined to be compatible with the architecture of the World Wide Web in general, and the Semantic Web in particular. OWL uses both URIs for naming and the description framework for the Web provided by RDF to add the following capabilities to ontologies: Ability to be distributed across many systems; Scalability to Web needs; Compatibility with Web standards for accessibility and internationalization; Openess and extensiblility; OWL builds on RDF and RDF Schema and adds more vocabulary for describing properties and classes: among others, relations between classes (e.g. disjointness), cardinality (e.g. "exactly one"), equality, richer typing of properties, characteristics of properties (e.g. symmetry), and enumerated classes. This site provides further resources on OWL.
Rights:
Copyright: Unknown
Access: Freely available.
Date of creation and last modification: 2004-09-27
Format of Resource: text/html
Educational Level: Metadata Architects

Created by Anita Coleman