Topic maps, a technology for knowledge organisation

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Topic maps, a technology for knowledge
organisation

• Presentation at ELAG 2004
• Nils Pharo

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Schedule

• Topic maps is a standard for organising digital
  content
• ISO certified in 2002 (ISO 13250)
• Used for structuring web sites, knowledge
  management

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The basic elements of topic maps

• Topic maps consist of
• Topics
• Associations
• Occurrences
• i.e. the TAO of topic maps (Pepper, 2002)

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Ontologies

• An ontology contains the topic maps input
• Examples of ontologies are thesauri, taxonomies,
  word-nets, etc
• Ontologies are not necessarily structured
  hierarchically

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Topic map technology

• XTM XML Topic Maps
• HyTM SGML based
• Topic map engines using databases of various
  kinds
• XTM XSL

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Example of XTM 1
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Example of XTM 2
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Example of XTM 3
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Characteristics of topic maps

• topics have names
• topics are knit together using associations
• a topic may be categorised by an unlimited number
  of topic types
• topic types are topics on a higher level of
  abstraction
• association types are association on a higher
  level of abstraction
• occurrences may be external or internal to the
  topic map
• topics can be disambiguated using subject
  indicators

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Topic maps for knowledge organisation

• Two challenges
• Hierarchical versus associative structuring
• Published Subject Indicators

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Hierarchies and networks

• Hierarchical in the thesaurus tradition with
  strict rules on what associative relationships
  should be allowed
• or
• Open up for unlimited implementation of
  associative relationships

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Published Subject Indicators

• PSIs contain definitions of subjects
• Who should provide such definitions?
• Centralised control or principle of natural
  selection?
• LIS traditionally aimed for control
• WWW of anarchistic nature