Zthes

1
Zthes

• Z39.50 Profile for Thesaurus navigation
• Sebastian Hammer

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Why?

• Z39.50 is good at straight searching - type in
  your query and cross your fingers.
  
• Z39.50 SCAN offers browsing of a flat list of
  possible terms - a window into the index.
  
• But...
• Users are accustomed to browsing hierarchical
  structures

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What is a thesaurus?

• ISO2788 - a general reference model for thesauri
• A thesaurus is a collection of interrelated
  terms
  
• Narrower (more specific) Term
• Broader (more general) Term
• Related Term
• Synonyms (Use-that-term-instead)

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Zthes Profile

• Zthes allows a Z39.50 client to navigate through
  a thesaurus structure hosted on a remote
  server.
  
• Uses existing protocol facilities (search,
  retrieval).
  
• Does require GRS-1 and multiple attribute set
  support.

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Zthes Database Model

• All records may contain
• The term itself (eg. aircraft)
• A qualifier (eg. military)
• Scope Note (prose text about term usage)
• Term ID
• Admin info
• Term type
• Relations

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Records - term types

• Term Type - the type of record
• A record may represent
• a preferred (index) term
• a non-preferred term (a synonym for something
  else)
  
• A node label

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Records - relations

• Relations consist of
• The term in question (plus qualifter)
• The term ID (unique in database)
• The type of the term
• The type of relationship
• The language of the other term
• Possibly the address of a different Z39.50/Zthes
  target/db

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How is it used?

• A well-known search is used to get to the
  beginning of the thesaurus
  
• Alternative A search for (parts of) a term name
  gets back one or more matches
  
• Client looks at term relations to navigate
  thesaurus
  
• Search for term-id to get new terms
• Similar to Hyper-link searching.

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Status

• Third public draft for discussion and testing
• The Editor Mike Taylor - mike_at_tecc.co.uk
• The Z39.50 Maintenance agency profile page