The Dewey Decimal and Library of Congress library classification systems are the two most common systems in the United States and among the most popular world-wide. These systems organize resources like books or other media by concept and assign call numbers that are, in part used to shelve and retrieve materials. The Dewey Decimal Classification (DDC) is used predominantly in public libraries in the United States while the Library of Congress Classification (LCC) is used primarily in academic libraries.

Characteristics

The Dewey Decimal Classification (DDC) was first published by Melvil Dewey in 1876, and included a detailed justification for his use of decimal notation. DDC decimal notation id can be expanded or reduced as needed by libraries. It was designed for medium and small sized collections, including those found in public libraries, school libraries, and small academic libraries. It consists of ten numeric classes that represent broad fields of study. Using numbers, each class is divided into ten divisions or subclasses. During the cataloging process, each item is assigned a three-digit DDC number that represents class, division, and section, followed by a cutter number that identifies the author. For example, the call number 813.54 M37 includes 800 for the main class of literature, 810 for the division of American literature in English, 813 for American fiction in English, and the cutter M37 for the author.

The Library of Congress Classification (LCC) was introduced in 1900, based on the collection of the Library of Congress, the largest library in the world. LCC was adopted by other institutions with larger or specialized collections, such as those found in academic libraries and research libraries. In 2019, 81 percent of US academic libraries and 93 percent of Nigeria's academic libraries used the Library of Congress Cataloging system. LCC has 21 main classes, each designated with a letter of the alphabet, excluding I, O, W, X, and Y which are used to accommodate special needs of libraries that use the classification scheme. Its alpha-numeric call numbers include four parts: class/subclass, topic, cutter number, and publication date. For example, HV4708 .R83 2011, where HV stands for social sciences, 4708 is the topic social welfare, .R83 is the cutter number which represents the author, and 2011 is the year of publication.

Both classification systems are used to create a functional topical order of the resources on the library shelves. They vary in their notation: DDC is a numeric classification system, while LCC is an alpha-numeric system. LCC was developed specifically for the Library of Congress collection, while DDC was created as a system that could be adapted to a variety of library sizes and specialties. D. Kent Halsted noted, "Neither scheme is perfect nor will ever be." As with any classification system, both DDC and LCC include the bias of their creators; in this case, both systems were developed by white, Christian, male academic scholars in late 19th century America.

There are various factors that determine which classification system a library uses. The global library cooperative OCLC notes that "A library should base its decision on close versus broad classification on the size of its collection and the needs of its users." Usually, the size of a library's collection determines whether it selects DDC or LCC. While DDC was designed for medium-sized libraries, LCC allows libraries with larger collections to be more specific or precise with classifications. Thus, DDC is preferred by institutions with collections under 200,000, while LCC is recommended if the collection includes more than 500,000 items. In the 1960s and early 1970s, many larger academic libraries changed from Dewey Decimal Classification to Library of Congress Classification. After converting the college's library from DCC to LCC in 2021, West Coast Baptist College's director of library services Alyssa Sultanik concluded,

LCC tends to divide resources into smaller subclasses and may be more suitable for larger collections. Several factors can play a part in the success of LCC, such as the practicality of LCC for academic libraries, the ease of use in a specialized collection, and the ability to grow for expanding libraries and the ability to easily add new topics as needed. The collection size, depth of the materials, and intended use of the library collection should be considered when choosing between classification systems...Smaller collections may be more suited for DDC because of the classification's more generalized nature.

Comparison

The following table compares the organization of resources by the Dewey Decimal and Library of Congress classification systems. It includes all 99 second-level (two-digit) Dewey Decimal classes (excluding 040), and all second-level (two-digit) Library of Congress classes.

Dewey DecimalLibrary of CongressDescriptionRef.
000A, AZ, QA, TA, Z4–659Computer science, knowledge, and general works; history of scholarship and learning
010AI, Z1001–8999Bibliography, indexes
020Z4–1000.5Library and information sciences
030AE, AG, AYGeneral encyclopedic works, yearbooks, almanacs, dictionaries, directories
040Unassigned
050AN, APGeneral serials and their indexes, periodicals, journals
060AM, AS, AYGeneral organization and museology, academies and learned societies, museums, collectors and collecting, associations, organizations
070AN, PN, Z278–549News media, journalism, publishing, newspapers
080ACQuotations, collections, collected works, series
090Z4-115Manuscripts, rare books, history of books
100BPsychology and philosophy, philosophy history
110B, BD, BHPhilosophy history, metaphysics, speculative philosophy, aesthetics
120BD143–237Epistemology, speculative philosophy
130BF1001–1999Parapsychology, occult sciences, astrology
140B, BDPhilosophical schools of thought, speculative philosophy, philosophy history
150BF1–940Psychology
160BCLogic
170BJEthics
180B, BL, BQAncient philosophy, medieval philosophy, Eastern philosophy, religions, mythology,rationalism, Buddhism, philosophy history
190BModern Western philosophy, philosophy history
200BLReligion, mythology
210B, BLPhilosophy of religion, theory of religion, philosophy history, religions, mythology
220BSThe Bible
230BRChristianity and Christian theology
240BR, BTChristian practice and observance, doctrinal theology
250BR, BTChristian pastoral practice and religious orders
260BR, BTChurch organization, social work, worship
270BR, BTChristian church history
280BR, BXChristian denominations, religions
290BL, BM, BP, BQOther religions, Judaism, Islam, Buddhism, Theosophy, Baháʼísm
300H, HM, HN, HQ, HS, HTSocial sciences, sociology, anthropology, human ecology, anthropogeography
310HAStatistics
320HX, J, JA, JC, JF, JK, JL, JN, JQ, JS, JV, JXPolitical science, socialism, communism, anarchism, political theory, theory of the state, Constitutional history, local government, colonies and colonization, emigration and immigration, international law, international relations
330HB, HC, HD, HE, HF, HG, HJEconomics, economics theory, economics history, transportation, communication, commerce, finance, public finance, environmental sciences
340JX, K, KD, KE, KF, KG, KH, KJLaw, international law, law of the United Kingdom, law of Ireland, law of Canada, law of the United States, law of Latin America, law of South America, law of Europe
350JF, JS, U, VPublic administration and military science, constitutional history, local government, naval science
360HN, HVSocial problems, social services, social history, social reforms, social pathology, criminology
370LEducation
380HE, HFCommerce, communications, and transport
390BJ, CE, GR, GTCustoms, etiquette, folklore, calendar, manners
400P, AGLanguage, philology, linguistics, dictionaries
410PLinguistics, philology
420PEEnglish language, Old English languages, English philology
430PD, PFGermanic languages, Germanic philology, West Germanic language, West Germanic philology
440PCFrench language, Romance philology
450PCItalian language, Romanian language, Rhaeto–Romanic language, Romance philology, Romance languages
460PCSpanish language, Portuguese language
470PA, PCLatin language, Italic languages, classical philology, classical literature; modern Greek literature, Byzantine literature, medieval Latin literature, modern Latin literature, Romance philology
480PAClassical Greek language, modern Greek language, classical philology, classical literature, Byzantine literature, modern Greek literature, medieval Latin literature, modern Latin literature
490PB, PG, PH, PJ, PK, PL, PMOther Languages: Celtic language, Celtic literature, Slavic languages, Slavic literature, Baltic languages and literature, Albanian language, Albanian literature, Finno-Ugarian languages and literature, Basque language, Basque literature, Egyptian language and philogy, Coptic language and philogy, Hamitic language and philogy, Semitic languages,Semitic philology, Indo-Iranian languages, Indo-Iranian literature, Eastern Asian languages, Eastern Asian literature, Oceanian languages, Oceanian literature, African languages,African literatures, American Indian languages, artificial languages
500QScience
510QAMathematics, computer science
520QBAstronomy
530QCPhysics
540QDChemistry, crystallography
550QE, GCEarth sciences, geology, oceanography
560GF, GN, QE, QHFossils, prehistoric life, human ecology, anthropogeography, anthropology, geology, natural history, biology
570QH, QP, QRLife sciences, biology, natural history, microbiology
580QKBotany
590QLAnimals, zoology
600TTechnology (applied sciences)
610QM, R, RA, RB, RC, RD, RE, RF, RG, RJ, RK, RL, RM, RS, RT, RV, RX, RZMedicine, human anatomy, public health, pathology, internal medicine, surgery, ophthalmology, otorhinolaryngology, gynecology, obstetrics, pediatrics, dentistry, dermatology, therapeutics, pharmacology, pharmacy, nursing, Thomsonian medicine, eclectic medicine, homeopathy, other systems of medicine
620TA, TC, TD, TE, TF, TG, TJ, TK, TL, TN, TREngineering, hydraulic engineering, environmental engineering, sanitary engineering, highway engineering, roads and pavement, railroads, railway engineering, mechanical engineering, electrical engineering, nuclear engineering, motor vehicles, aeronautics, astronautics, mining engineering, metallurgy, photography
630S, SB, SD, SF, SH, SKAgriculture, plant industry, animal industry, plant culture, forestry, animal culture, aquaculture, fisheries, angling, hunting
640TT, TXHome management, family management, home economics, handicrafts, arts and crafts
650H, HA, HB, HC, HD, HF, HG, HMManagement, public relations, social sciences, statistics, economic theory, demography, economic history, commerce, finance, public finance
660TPChemical engineering
670TSManufacturing
680TS, TTManufacturing specific products, graphic arts
690THBuilding and construction
700N, NXArts, visual arts
710SBLandscaping, area planning, plant culture
720NAArchitecture
730NB, CJSculpture, ceramics, metalwork, numismatics
740NC, NKDrawing, decorative arts, design, illustration, applied arts, decoration, ornament
750NDPainting, drawing, design, illustration, painting, print media
760NC, ND, NEGraphic arts, printmaking, prints
770TRPhotography and photographs
780M, ML, MTMusic, instrumental music, vocal music, literature of music, music instruction
790GVSports, games, entertainment, recreation, leisure
800P, PNLiterature, rhetoric, criticism, language, literary history, literary collections, theater, oratory, journalism
810PS, PZAmerican literature in English, juvenile belles letters
820PR, PZEnglish literature, Old English literature, juvenile belles letters
830PT, PZGerman literature, Germanic literature, juvenile belles letters
840PQ, PZFrench literature, Romance literature, juvenile belles letters
850PQ, PZItalian literature, Romanian literature, Romance literature, juvenile belles letters
860PQ, PZSpanish literature, Portuguese literature, Romance literature, juvenile belles letters
870PQ, PZLatin literature, Italian literature, Classical philology, Classical literature, Byzantine literature, medieval Latin literature, modern Latin literature, juvenile belles letters
880PA, PZClassical Greek literature, modern Greek literature, classical philology and literature, juvenile belles letters
890PB, PG, PH, PJ, PK, PL, PZOther languages, Celtic languages, Celtic literature, Slavic languages, Slavic literature, Baltic languages and literature, Albanian languages, Albanian literature, Finno-Ugarian languages and literature, Basque language, Basque literature, Egyptian language and philology, Coptic language and philology, Hamitic languages and philology, Semitic languages, Semitic philology, Indo-Iranian languages, Indo-Iranian literature, Eastern Asian languages, East Asinan literature, Oceanic languages, Oceanian literature, African languages, African literature, juvenile belles letters
900CB, D, E, FHistory, history of civilization, topography, history of the United States, local history of the United States, history of North America except the U.S., history of South America
910G, GA, GBGeography, travel, mathematical geography, cartography, physical geography
920CD, CR, CS, CTBiography, genealogy, diplomatics, archives, seals, heraldry
930CB, CC, CN, DA, DAW, DB, DC, DD, DE, DF, DGHistory of ancient world (to ca. 499 A.D.), history of civilization, archaeology, epigraphy, inscriptions, classical antiquity, Great Britain, Central Europe, Austria, Lichtenstein, Hungary, Czechoslovakia, France, Andorra, Monaco, Germany, East Germany, Mediterranean, Greece, Italy, Malta
940DA, DAW, DB, DC, DD, DF, DG, DH, DJ, DJK, DK, DL, DP, DQ, DRHistory of Europe (ca 500 A.D.), Great Britain, Central Europe, Austria, Liechtenstein, Hungary, Czechoslovakia, France, Andorra, Monaco, Germany, East Germany, Greece, Italy, Malta, Belgium, Luxembourg, Holland, Eastern Europe, Soviet Union, Poland, Scandinavia, Spain, Portugal, Switzerland, Balkan peninsula
950DSHistory of Asia, China, Japan, Arabian Peninsula, Saudi Arabia, India, Iran (Persia)
960DTHistory of Africa, Libya, Tunisia, Egypt, Sudan, Ethiopia (Abyssinia), Eritrea, Algeria, West Africa, Central Africa, South Africa
970E, F1–1392History of North America, United States, Canada, Mexico
980F1401–3799History of South America, Central America, Brazil, Argentina, Chile, Bolivia, Peru, Venezuela
990DUHistory of other regions, Oceania, Australia, New Zealand, Melanesia, New Guinea

See also

Further reading

  • Billy, Amber; Nelson, Elizabeth; and Uhl, Rebecca. Inclusive Cataloging: Histories, Context, and Reparative Approaches. Chicago: ALA Editions, 2024. ISBN 979-8-89255-566-1.
  • Chan, Lois Mai. A Guide to the Library of Congress Classification, 6th ed. New York: Libraries Unlimited, 2016. ISBN 978-1440844331.
  • Chan, Lois Mai and Salaba, Athena. Cataloging and Classification: An Introduction. Lanham, Maryland: Rowman & Littlefield Publishers, Inc., 2016. ISBN 9781442232495.
  • Merkley, Carl. "The Library of Congress, Dewey Decimal, and Universal Decimal Classification Systems are Incomplete and Unsystematic". Evidence Based Library and Information Practice, vol. 6, no. 4 (2011): 134–136. doi.org/10.18438/B8QK7S.
  • Satija, M. P. The Theory and Practice of the Dewey Decimal Classification System. Hull: Chandos Publishing, 2013. ISBN 978-1843347385.
  • Scott, Mona L. Dewey Decimal Classification: A Study Manual and Number Building Guide, 22nd edition. New York: Libraries Unlimited, 2005. ISBN 978-1591582106.
  • Sroka, Marek. "Library of Congress Subject Headings, Dewey Decimal Classification and the Ambiguity of Subject Representation of Central, Eastern and South-Eastern Europe in American Knowledge Organization Systems." Central European and Balkan Studies, vol. 33 (November 21, 2024): 9–16. doi.org/10.4467/2543733XssB.24.001.20025
  • Weihs, Jean and Intner, Sheila S. Beginning Cataloging, 2nd edition. Bloomsbury Publishing, 2016. ISBN 9798216052197.

External links

  • (Library of Congress).
  • Ross, Geoffrey. (History, Philosophy, and Newspaper Library, University of Illinois).