Library classification

Library classification is a system used by librarians to organize library materials, including books, serials, audiovisual items, and digital objects, on shelves or in databases. These systems assign unique call numbers based on the subject content of each item, facilitating efficient information retrieval and browsing by library patrons. The practice is fundamental to library science and knowledge organization, enabling the systematic arrangement of vast library collections in institutions like the Library of Congress and the British Library.

Overview

The primary goal is to bring related materials together in a logical, helpful sequence on the library shelf. This is achieved by applying a standardized notation, often alphanumeric, which translates the subject of a work into a call number. This number is then used for shelving and inventory purposes. Early systems were often developed for specific collections, such as those at the Bibliothèque nationale de France, but evolved into universal schemes. The process is distinct from but complementary to subject headings used in catalogs, with classification providing a physical location while subject headings offer conceptual access.

Major classification systems

Globally, several major systems are in widespread use. The Dewey Decimal Classification (DDC), created by Melvil Dewey, is the world's most widely used system, particularly in public libraries and school libraries. The Library of Congress Classification (LCC) is predominant in large academic and research libraries, such as those at Harvard University and the University of Oxford. Other significant systems include the Universal Decimal Classification (UDC), which is heavily used in Europe and for bibliographies, and the Bliss bibliographic classification, used in some British institutions. Specialized schemes like the National Library of Medicine classification are used in fields like medicine.

Principles and theory

Theoretical foundations are deeply rooted in ontology and the philosophical organization of knowledge. Key principles include literary warrant, where the classification reflects the literature that exists, and user warrant, considering the needs of library patrons. Systems can be enumerative, like the Library of Congress Classification, listing all possible subjects, or faceted, like the Colon classification developed by S. R. Ranganathan, which combines elements from different facets. Ranganathan's Five laws of library science profoundly influenced modern theory, emphasizing that classification must save the time of the user.

Implementation and use

In practice, catalogers or classificationists analyze the content of a work, often consulting resources like the OCLC's WorldCat, to determine its primary subject. They then consult the classification schedule, such as the printed volumes of the Dewey Decimal Classification, to derive the appropriate notation. This call number is combined with other elements, like a Cutter number or the author's name, to create a unique identifier for shelving. The implementation directly affects library circulation and stack management, and is a core module in integrated library systems like those from Ex Libris Group.

Comparison of systems

Each major system has distinct characteristics and typical applications. The Dewey Decimal Classification is known for its hierarchical, decimal notation and is often taught in programs like those at the University of Illinois Urbana-Champaign. The Library of Congress Classification uses a mixed notation of letters and numbers, allowing for greater expansion in specific areas like law or history, and is maintained by the Library of Congress. The Universal Decimal Classification, managed by the UDC Consortium, is highly faceted and used for complex information science applications. The choice between systems often depends on the size of the collection, the user community, and institutional tradition.

Challenges and future trends

Contemporary challenges include classifying non-traditional materials like websites and digital library objects, and addressing inherent bias in historical systems that may marginalize non-Western perspectives. The rise of the Semantic Web and technologies like Resource Description Framework (RDF) are promoting more flexible, machine-readable approaches to knowledge organization, such as ontologies. Future trends point toward greater integration of traditional schemes with linked data projects and the development of more dynamic, user-centered classification in digital environments, influenced by work at institutions like the Massachusetts Institute of Technology.

Category:Library science Category:Knowledge organization