Making Visible Hidden Relationships in the Dewey Decimal Classification: How Relative Index Terms Relate to DDC Classes

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Making Visible Hidden Relationships in the
Dewey Decimal Classification How Relative Index
Terms Relate to DDC Classes
10th International ISKO Conference August 6,
2008 Rebecca Green Assistant Editor Dewey
Decimal Classification
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Example class

• 796.86 Fencing
• Including bojutsu, kendo
• Class here sword fighting
• RI Bojutsu
• Fencing (Swordplay)
• Kendo
• Sword fighting
• Swordplay

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DDC classes

• Class as gathering point for set of topics
• Caption
• Including concepts
• Class here concepts
• Topics either equal / approximate whole of class
  or are in standing room in class

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Topics in classes

• Approximating the whole vs. standing room
• Standard subdivisions can only be added for
  topics that approximate the whole of the class,
  not for those in standing room
• Future expansion anticipated for topics in
  standing room, not for those that approximate the
  whole
• Topics in class-here notes approximate the whole
  of the class topics in including notes are in
  standing room

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Relative Index terms and class topics

• Explicitly Relative Index terms index class as
  whole
• Implicitly Relative Index terms associated with
  specific topics in class
• Specific associations not recorded
• Thus, unknown if Relative Index term topic
  approximates the whole of the class or is in
  standing room there
• Project attempts to make this designation
  automatically

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Motivation

• Correct decision on addition of standard
  subdivisions
• Maintenance of scheme If topic moves to another
  class, associated Relative Index term should, too
• Support automated operations on scheme, e.g.,
  creation of derived versions

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Difficulties

• Identification of topics
• Topics in caption
• In multitopic caption, topics may approximate
  whole or be in standing room
• Paraphrase relationship between topics in
  schedules and Relative Index terms
  (morphological, syntactic, semantic)

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Example

• 133.3 Divinatory arts
• Including fortune-telling by bones,
  dice, pendulum
• Relative Index terms
• Bonesdivination
• Dicedivination
• Pendulumsdivination

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Standard subdivisions note

• 749 Furniture and accessories
• Standard subdivisions are added for furniture and
  accessories together, for furniture alone

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Two-phase approach

• In schedules
• Isolate topics
• Determine if topics equal / approximate whole of
  class (AW) or are in standing room (SR)
• Match Relative Index terms to schedule topics,
  using series of increasingly more relaxed
  strategies

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Topic isolation

• Sign languages used primarily for purposes other
  than communication of deaf people
• Systems programs Operating systems
• Satellites and rings eclipses, transits,
  occultations
• Religious experience, life, practice cant parse
  reliably

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Approximates-the-whole topics

• All topics in class-here note
• Topic in single topic caption
• Topic in multitopic caption, with note that
  standard subdivisions are added for
• Any or all topics in heading
• Either or both topics in heading
• The specific topic alone

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Standing room topics

• All topics in including notes
• Topic in multitopic caption, with note for adding
  standard subdivisions, not meeting criteria for
  approximating the whole
• Topic in multitopic caption, without note for
  adding standard subdivisions, that matches topic
  in subordinate caption

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Matching RI terms to topicsEXACT match
121 Epistemology (Theory of knowledge) 121.63
     Certainty and probability Standard
subdivisions are added for either or both
topics in heading RI
Probabilitiesepistemology (AW)
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Matching RI terms to topicsIN match

• 620 Engineering
• 627.52      Irrigation
• Class here construction and use of irrigation
  canals
• RI Irrigation
  canalsengineering (AW)

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Matching RI terms to topicsKEYWORD match

• 384.14      Activities and services
• Including Morse and other code telegraphy,
  printing telegraphy stock tickers, teletype,
  telex comprehensive works on facsimile
  transmission
• RI Morse code telegraphy (SR)

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Matching RI terms to topicsKEYWORD match

• 384.51      Satellite communication
• RI Communications
  satellites (AW)
• 384.54      Radiobroadcasting
• Class here public broadcasting (noncommercial
  broadcasting), public aspects of amateur radio,
  interdisciplinary works on radiobroadcasting and
  television broadcasting
• RI Noncommercial radio (AW)

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Matching RI terms to topicsPARTIAL (50) match

• 748    Glass
• 748.6      Methods of decoration
• RI Decorative treatmentglass
  (AW)

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Results
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Future improvements (1)

• Observe hierarchical force
• 302 Social interaction
• Class here . . . social psychology
• 302.24 Content
• Including gossip, rumor
• RI Rumorsocial psychology

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Future improvements (2)

• Dont require match on Relative Index qualifier
• 335.2 Systems of French origin
• Including Babouvism, Icarianism
• RI Babouvism (Socialist school)

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Future improvements (3)
Introduce stopwords for general terms 748
   Glass 748.6      Methods of decoration
RI Decorative treatmentglass (AW)
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Future improvements (4)

• Locally reverse treatment of main heading and
  subheading
• 220 The Bible
• 224 Prophetic books of Old Testament
• 224.1 Isaiah (Isaias)
• RI Bible. O.T.--Isaiah