Library Classification Systems

 Three classification systems:

Library of Congress (LOC)

Dewey Decimal System (DDS)

Superintendent of Documents (SuDoc)

 

Call Numbers

The call number is the letter/number combination assigned to each book, bound journal or other material. The call number is the unique identifier of each book, journal or other material.

The call number is located on the spine or front cover of the book, or material.

Library books and materials are placed in call number order on the shelves.

Each library classification system assigns unique call numbers using different rules.

Library of Congress Classification System

Created to organize material for the U.S. Congress.

The first letter of the call number is the class, or broad subject area that is determined by the contents of the book. 

Library of Congress

History

The Library of Congress classification system was developed in 1899 by the Librarian of Congress Dr. Herbert Putnam and his Chief Cataloger Charles Martel.

The Library of Congress system is founded on 21 major classes, each class being given an arbitrary capital letter between A-Z, with 5 exceptions: I, O, W, X, Y. 

Dewey Decimal Classification System

    Melville Dewey created an organizational system for libraries, in 1876, based on the decimal system.

The Dewey Decimal Classification System (DDC) is based on ten (10) classes into which 

information is placed. Within each of those classes are ten (10) divisions, and within each 

division are ten (10) sections, and so on. 

In some libraries, the Dewey Decimal system is used only for material in the Juvenile collection, but Dewey is the most often used library classification system worldwide.

 

Dewey classes

The basic Dewey Decimal classes are: 

 

000    Generalities

100    Philosophy and Psychology

200    Religion

300    Social Sciences

400    Language

500    Natural Sciences and Mathematics

600    Technology (Applied Science)

700    The Arts

800    Literature and Rhetoric

900    Geography and History

  

The Dewey Decimal System and How to Use It

      Melvil Dewey (1851 ‑ 1931) was a man who believed in organization. Even as a child he was busy  devising a way to arrange his family's pantry to make it more efficient. Before his system of classifying library books was adopted, many libraries relied on systems that filed books by size or color‑cumbersome and not very useful methods at best. While working as a librarian at Amherst College, Dewey developed a system that is used by most school and small public libraries today. Published anonymously in 1876, his classifications divide nonfiction books into ten  broad categories:

000 ‑ 099

General works (encyclopedias and similar works)

100 ‑ 199

Philosophy (how people think and what they believe)

200 ‑ 299    

Religion (including mythology and religions of the world)

 300 ‑ 399    

Social sciences (folklore and legends, government, manners and customs, vocations)

400 ‑ 499    

Language (dictionaries, grammars)

500 ‑ 599   

Pure science (mathematics, astronomy, chemistry, nature study)

600 ‑ 699    

Technology (applied sciences ‑ aviation, building, engineering, 

                           homemaking)

 

      700 ‑ 799     Arts (photography, drawing, painting, music, sports)

 

      800 ‑ 899     Literature (plays, poetry)

 

      900 ‑ 999     History (ancient and geography, travel)

 

          Each of these sections is further divided for accuracy in classification. For example, the numbers 500 ‑ 599 cover the pure sciences, such as astronomy, chemistry, mathematics, paleontology,  and physics. Each of these areas has its own division and section number. All books on mathematics are assigned numbers in the 510 to 519 range; mathematics is then broken down into types, such as algebra, arithmetic, and geometry. Geometry's specific number is 513, which can be subdivided through the use of decimal points to      provide ten basic categories. Additional digits can be added, creating an ever more precise  categorization system.

 

          Books are arranged alphabetically within each classification by the first letters of the author's last name. Therefore, a library that has several books on American history of the colonial period will assign the same basic number (973.2) to all the books and shelve them alphabetically.  Dewey's aim was to create a system that would be simple enough for even casual users to understand, but complex  enough to meet a library's expanding    needs. His system was developed to meet the needs of many libraries. A second popular system was created to fit the requirements of a specific library, the Library of Congress. This system, now in wide use, is even more detailed and has the advantage of being able to accommodate growth of knowledge in unexpected areas.  The Library of Congress Classification System The Library of Congress Classification System is used in most large public and university libraries today. A Library of Congress (LC) classification number contains three lines, a letter at the top, a number in the middle, and a letter/number combination at the bottom. The Library of Congress went through several systems before devising its own method. Because the Library of Congress contains almost every book ever published in the United States, as well as  valuable tapes and research materials, it needs a highly flexible system. The Library of Congress  Classification System contains 20 classes:

 

      A:     General works

 

      B:      Philosophy and religion

 

      C:      History‑auxiliary sciences

 

      D:      History and topography (except America)

 

    E‑F:     American history

 

      G:      Geography, anthropology, folklore, man and customs, recreation

 

      H:      Social sciences

 

      J:        Political sciences

 

      K:       Law of the United States

 

      L:       Education

 

      M:      Music and books on music

 

      N:      Fine arts                             

 

      P:         Language and literature

 

      Q:      Science

 

      R:      Medicine

 

      S:      Agriculture and plant and animal industry

 

      T:      Technology

 

      U:     Military science

 

      V:     Naval science

 

      Z:    Bibliography and library science

 

   Each of these classes can be divided into a subclass with the addition of a second letter. By  adding numbers, the category becomes even more specific. The flexibility of the system becomes apparent when one sees that the alphabet permits 26 subdivisions of any one class. Each of the subdivisions can be broken down further by using the numbers 1 to 9999.  Librarians recommend that researchers turn to  Subject Headings Used in the Dictionary Catalog of the Library of Congress for assistance. Because the LC system groups related topics together, a researcher may discover unexpected, related avenues to pursue.