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Chapter 13. Classification and Categorization

Chapter Outline

  • Introduction

  • Basic Concepts

  • Notation

  • Components of a Classification Scheme

  • How to Classify

  • Call Numbers

  • Modern Library Classification Systems

Key Takeaways

This chapter provides an introduction to classification theories and bibliographic classification schemas, meaning classification systems created specifically for the classification, organization, and arrangement of information resources.

Categorization

Categorization is dividing the world of entities based on their characteristics, features, or other criteria and the similarities between the entities. Often the concept of categorization and classification is used interchangeably but there are some differences. 

Classification

Classification begins with the universe of knowledge as a whole and divides it into successive stages of classes and subclasses with chosen characteristics, also called facets, as the bases for each stage. In the LIS field, classification schemas representing the universe of knowledge as a whole or a particular domain are used to classify information resources based on the aboutness of their intellectual content. The Dewey Decimal Classification (DDC) and the Library of Congress Classification (LCC) are the most widely used library classification systems today.

Classification structures

Traditional library classification schemes, specifically hierarchical systems, tend to list all subjects and their subdivisions and provide ready-made symbols for them. These schemes are called enumerative classification schemas. 

 

Modern classification theory places emphasis on facet analysis (breaking up a subject into its component parts) and synthesis (reassembling those parts as required by the document to be represented). These classification systems are known as faceted or analytico-synthetic classifications. Instead of enumerating all subjects in a hierarchical structure, a faceted classification scheme identifies the basic components of subjects and lists under each discipline or main class the elements or aspects that are topically important within that class. 

Arrangement

Classification of documents also serves as the basis for the topical arrangement of library collections. It is common practice to classify an information resource using a classification schema, assigning only one class number (code or notation), even if multiple topics and classes apply, and using the notation as the basis for the construction of a call number with the addition of a notation to represent the particular item. This call number (a combination of the class number and the work/item mark) serves as the item's location marker within the collection. 

Chapter References/Notes

  1. Jacob, E. K. (2004). Classification and categorization: A difference that makes a difference. Library Trends, 52(3), 515–540.

  2. Hjørland, B. (2017). Classification. Knowledge Organization, 44(2), 97–128. Also available in ISKO Encyclopedia of Knowledge Organization, eds. Birger Hjørland and Claudio Gnoli, http://www.isko.org /cyclo/classification

  3. ALCTS/CCS/SAC/Subcommittee on Metadata and Subject Analysis. (1999). Subject data in the metadata record: Recommendations and rationale. Retrieved from http://www.ala.org/alcts/resources/org/ cat/subjectdata_record

  4. ALCTS/CCS/SAC/Subcommittee on Metadata and Classification. (1999). Final report. Retrieved from www.ala.org/alcts/mgrps/camms/cmtes/sac/inact/metadataandclass/metadataclassification

  5. Golub, K., Hagelbäck, J., & Ardö, A. (2018). Automatic classification using DDC on the Swedish Union Catalogue. In 18th European Networked Knowledge Organization Systems Workshop (NKOS 2018), Porto, Portugal, September 13 (pp. 4–16).

  6. Lin, X., Khoo, M., Ahn, J., Tudhope, D.,Binding, C., Massam, D., & Jones, H.(2017).Mapping metadata to DDC classification structures for searching and browsing. International Journal On Digital Libraries, 18(1), 25–39.

  7. Ahn, J., Lin, X., & Khoo, M. (2014). Dewey decimal classification based concept visualization for information retrieval. Knowledge Maps and Information Retrieval Workshop at Digital Libraries’ 2014.

  8. Waldhart, T. J., Miller, J. B., & Chan, L. M. (2000). Provision of local assisted access to selected internet information resources by ARL academic libraries. Journal of Academic Librarianship, 26(2), 100–109.

  9. Korfhage, R. R. (1997). The matching process. In Information Storage and Retrieval. New York: Wiley (pp. 79–104).

  10. Chan, L.M (2001).Exploiting LCSH, LCC, and DDC to retrieve networked resources. In A.M.Sandberg-Fox (Ed.), Proceedings of the bicentennial conference on bibliographic control for the new millennium: Confronting the challenges of networked resources and the web. Washington, DC: Library of Congress (p. 164).

  11. Chan, 2001, p. 164.

  12. Mai, J.-E. (2003). The future of general classification. Cataloging and Classification Quarterly, 37(1/2), 3–12.

  13. Zeng, Marcia Lei. (2019). Interoperability. Knowledge Organization, 46(2), 122–146.

  14. Ranganathan, S. R. (1963). Colon classification (6th ed., reprinted with amendments). Mumbai, India: Asia Publishing House.

  15. Dewey, M., Mitchell, J. S., Beall, J., Green, R., Martin, G., & Panzer, M. (2011). Dewey decimal classification and relative index (Ed. 23) (pp. xli–xlv). Dublin, Ohio: OCLC Online Computer Library Center, Inc.

  16. Dunkin, P. S. (1969). Cataloging U.S.A. Chicago, IL: American Library Association (pp. 116–122).

  17. Merrill, W. S. (1939). Code for classifiers (2nd ed.). Chicago, IL: American Library Association (pp. 3–7).

 

Additional Readings

Here, you will find readings specific to the contents of this chapter.

You may find more readings about similar topics on the Cataloging and Classification Web Resources page

Categorization
  • Rosch, E. (1978). "Principles of categorization."  In Rosch, E. & Lloyd, B.B. (eds), Cognition and Categorization, Lawrence Erlbaum Associates, Publishers; pp. 27–48

  • Categorization. (2017). Wikipedia. Retrieved from: https://en.wikipedia.org/wiki/Categorization

Classification
  • Hjørland, B. (2017). Classification. ISKO Encyclopedia of Knowledge Organization. Retrieved from http://www.isko.org/cyclo/classification

  • Hjørland, B. (2018). Indexing: Concepts and theories. ISKO Encyclopedia of Knowledge Organization. Retrieved from http://www.isko.org/cyclo/indexing

  • Clarke, R.I. (2021). “Library classification systems in the U.S.: Basic ideas and examples.” Cataloging & Classification Quarterly, 59(2-3), 203-224, DOI: 10.1080/01639374.2021.1881008

  • Kwasnik, B.H. (2000). “The role of classification in knowledge represantation [sic] and discovery.” School of Information Studies - Faculty Scholarship. 147. Retrieved from https://surface.syr.edu/istpub/147

Standards and Tools
  • Cutter, C. A., Jones, K. E., Swanson, P. K., & Swift, E. M. (1969). Cutter-Sanborn three-figure author table (Swanson-Swift revision). Chicopee, MA: H. R. Huntting Company.

  • Cutter, C. A., Swanson, P. K., & Swift, E. M. (1969). C. A. Cutter’s three-figure author table (Swanson-Swift revision). Chicopee, MA: H. R. Huntting Company.

  • Cutter, C. A., Swanson, P. K., & Swift, E. M. (1969). C. A. Cutter’s two-figure author table (Swanson-Swift revision). Chicopee, MA: H. R. Huntting Company.

  • Dewey, M., Mitchell, J. S., Beall, J., Green, R., Martin, G., & Panzer, M. (2011). Dewey decimal classification and relative index (Ed. 23). Dublin, Ohio: OCLC Online Computer Library Center, Inc.

  • Dewey, M., & Mitchell, J. S. (2012). Abridged Dewey decimal classification and relative index (Ed. 15). Dublin, Ohio: OCLC, Online Computer Library Center, Inc.

  • Library of Congress. (2002-2011, May). Library of Congress Classification weekly list. Retrieved from http://www.loc.gov/aba/cataloging/classification/weeklylists/

  • Library of Congress. (2011, May-). Library of Congress Classification (LCC) approved list. Retrieved from http://www.loc.gov/aba/cataloging/classification/

  • Library of Congress. (2014-). Classification web: World Wide Web access to Library of Congress classification and Library of Congress subject headings. Retrieved from www.classificationweb.net/

  • Library of Congress, Cataloging Policy and Support Office. (1901–). Classification. Washington, DC: Library of Congress.

  • Library of Congress, Cataloging Policy and Support Office. (1995). Subject cataloging manual: Shelflisting (2nd ed.). Washington, DC: Library of Congress.

  • Library of Congress, Cataloging Policy and Support Office. (2008). Subject cataloging manual: Classification (2008 ed.). Washington, DC: Library of Congress.

  • Library of Congress, Policy and Standards Division. (2009-). Classification and Shelflisting Manual. Washington, DC: Library of Congress. Retrieved from https://www.loc.gov/aba/publications/FreeCSM/freecsm .html 

  • National Library of Medicine (U.S.). (2019). NLM classification 2019 winter edition. Retrieved from www.nlm.nih.gov/class/

  • OCLC, Online Computer Library Center. (2011). Webdewey. Retrieved from www.dewey.org/webdewey/

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