The UNESCO Thesaurus
Meeting for Managers of UNESCO Documentation Networks
Meron EwketuUNESCO Library
June 8 2005
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Definition and function of a thesaurus
What is it?A hierarchically structured and controlled list of
terms used for indexing and retrieving information in UNESCO’S fields of competence.
The UNESCO Thesaurus is used by the UNESCO library to catalog its holdings and in collective cataloging projects with field offices, by outside organizations such as the UK Records Office, and in several integrated library management systems.
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Definition and function of a thesaurus (2)
Why do we need it?
• Language is rich and varied and in constant evolution
• So many terms to denote the same concept
• drugs vs. medicines, indigenous populations vs. natives, Gypsies vs. Roma, Myanmar vs. Burma
• Need to use a controlled vocabulary in order to avoid loss of information arising from the ambiguity of natural language: The UNESCO Thesaurus
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Characteristics Multidisciplinary:
It covers the major fields of knowledge that constitute the scope of UNESCO. It also includes the names of countries and groupings of countries.It contains 7,000 terms in English, 8,600 terms in French and 6,800 in Spanish
Multilingual:Available in English, French and Spanish…and very soon in Russian
Structured according to the ISO standards 2788 and 5964
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Historical background
• The 1st edition of the UNESCO thesaurus was released in 1977
• The 2nd updated, revised and restructured edition was released in 1995
• The online version on web Isis was released in 2000 in English, followed by the French and Spanish version in 2003 and 2004 respectively
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Thesaurus structure
• Terms• Term relationships
i. Equivalence relationship (USE/UF)ii. Hierarchical relationship (BT/NT)iii. Associative relationship (RT/RT)
• And Scope notes (SN)Some descriptors are accompanied by a SN to explain their meaning or
delimit their intended use
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Equivalence relationships (synonyms/ near-synonyms): Use / Used for (UF)
Non preferred terms serve as entry points, connecting the terms that users have in mind, e.g. Green tourism with the preferred term, or descriptor applied by the indexer, i.e. Ecotourism
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Hierarchical relationships: Broader term (BT) / Narrower term (NT)
Helps users to better define, expand or focus their search by selecting more specific or generic descriptors
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Associative relationships (non-hierarchical): Related terms (RT)
Invites the user to also consider other terms which are closely related to what he is looking for. Users interested in the keyword rights of the child might also be interested in child labour, etc.
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Scope notes (SN)
The SN specifies what the descriptor covers and excludes other possible meanings
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The main purpose of the thesaurus is
• Helping indexers choose the appropriate keywords when describing subject content of documents
• Helping users identify the most appropriate keywords with which to search and retrieve pertinent information from the online catalogue
Thus allowing indexers and users to "speak the same language" and bridging the gap between documents and users.
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Indexing
The indexer will extract the concepts contained in the document and translate these into descriptors from the UNESCO thesaurus
The concept of “scientific diasporas” can thus be rendered with the descriptors “brain drain” and “scientists”…
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Searching the online catalogue Unesbib/unesdoc
Then the searcher refering to the same thesaurus selects appropriate keywords and formulates his query in the online catalogue
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Advantages of using the thesaurus
• Consistency in indexing• Different information providers, or indexers use the same terms
to describe the same concept
• Cross language information retrieval in searching • Allows users to input query in one language, language in which
one is conversant, and retrieve documents written in another language
• Regularly updated • Follows closely the evolution of the terminology in international
development organizations and in particular, in UNESCO’s field of competence
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Thesaurus: further developments
• Translation of the thesaurus into Russian (in progress)
• New search possibility: searching the UNESCO online catalogue via the thesaurus (in progress)
• Integration of the thesaurus in the UNESCO web content management system (Symplify)
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Access to the UNESCO Thesaurus
• Offline
•Print edition: UNESCO Thesaurus, 1995 (now out of print)
•CD-ROM: UNESCO Thesaurus, 2004 (published every year)
• Online
•http://databases.unesco.org/thesaurus/
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Questions? Comments? Suggestions…
• Meron [email protected]
• Patrick HubyTechnical [email protected]
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