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

1. 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

2. Example class • 796.86 Fencing • Including bojutsu, kendo • Class here sword fighting • RI: Bojutsu • Fencing (Swordplay) • Kendo • Sword fighting • Swordplay

3. 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

4. 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

5. 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

6. 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

7. 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)

8. Example • 133.3 Divinatory arts • Including fortune-telling by bones, dice, pendulum • Relative Index terms: • Bones—divination • Dice—divination • Pendulums—divination

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

10. 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

11. Topic isolation • Sign languages used primarily for purposes other than communication of deaf people • Systems programsOperating systems • Satellites and rings; eclipses, transits, occultations • Religious experience, life, practice [can’t parse reliably]

12. 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

13. 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

14. Matching RI terms to topics:EXACT match 121 Epistemology (Theory of knowledge) 121.63      Certainty and probability Standard subdivisions are added for either or both topics in heading RI: Probabilities—epistemology (AW)

15. Matching RI terms to topics:IN match • 620 Engineering • 627.52      Irrigation • Class here construction and use of irrigation canals • RI: Irrigationcanals—engineering(AW)

16. Matching RI terms to topics:KEYWORD match • 384.14      *Activities and services • Including Morse and other code telegraphy, printing telegraphy; stock tickers, teletype, telex; comprehensive works on facsimile transmission • RI: Morsecode telegraphy (SR)

17. Matching RI terms to topics:KEYWORD match • 384.51      *Satellitecommunication • RI: Communicationssatellites (AW) • 384.54      *Radiobroadcasting • Class here public broadcasting (noncommercial broadcasting), public aspects of amateur radio, interdisciplinary works on radiobroadcasting and television broadcasting • RI: Noncommercialradio(AW)

18. Matching RI terms to topics:PARTIAL (50%+) match • 748    Glass • 748.6      Methods of decoration • RI: Decorative treatment—glass(AW)

19. Results

20. Future improvements (1) • Observe hierarchical force • 302 Social interaction • Class here . . . social psychology • 302.24 Content • Including gossip, rumor • RI: Rumor—social psychology

21. Future improvements (2) • Don’t require match on Relative Index qualifier • 335.2 Systems of French origin • Including Babouvism, Icarianism • RI: Babouvism (Socialist school)

22. Future improvements (3) • Introduce stopwords for general terms • 748    Glass • 748.6      Methods of decoration • RI: Decorative treatment—glass(AW)

23. 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