Restricted Vocabularies

Restricted vocabularies are usually defined as hierarchies of terms. Difference types have progressively well defined semantics. To move from the current state of information retrieval to a Semantic Web we must migrate from these existing resources to the new ontology resources - with even better defined semantics.

Term/Category Lists

The UK Government Category List (GCL) is a classified list of headings or controlled vocabulary for use with the Subject element of the e-GMS. The total number of headings in the scheme is around 350, of which 12 are top level headings and about 120 are at the second level.

Classification Schemes

The Physics and Astronomy Classification Scheme® (PACS®) is a hierarchical subject classification scheme designed to classify and categorize the literature of physics and astronomy for journal subject indexes.

Thesauri

Each major field has a major existing thesaurus, in some cases there are many.

• Art - Getty AAT - English language, 28000 main terms, 120000 terms
• Social Science - ELSST, 4 languages, 1107 main terms, 5000 terms
• Space Science - NASA Thesaurus, English, 20000 main terms, 70000 terms
• Fields in which the European Communities are active - EuroVoc EC Thesaurus, 11 langauges, 6075 main terms, 9000 relationships
• education; science; culture; social and human sciences; information and communication; and politics, law and economics - UNESCO Thesaurus, French (FR) and Spanish (SP) equivalents of English preferred terms