Say the word "library" to a literate person and chances are one of the reminiscences it evokes will contain the word "Dewey."
As David Smith, chief of the Library's Decimal Classification Division likes to point out, much of the world associates Dewey not only with libraries but with growing up. "For many, books arranged by the Dewey Decimal Classification [DDC] system, whether in a local public library or at school, represented their first organized encounter with the world of information, amazement and amusement -- all in books packed onto shelves with a seeming artlessness that only in retrospect is revealed as art of the highest order," Mr. Smith said.
Even those who later ply their trade in the carrels and stacks of the many large U.S. research libraries that use the Library of Congress Classification rather than the DDC often retain an affection for the simplicity of the Dewey scheme of arrangement. But it would be a mistake to see simplicity as the main hallmark of Dewey.
"Coming to terms with Dewey is like playing the piano," Mr. Smith said. "A simple tune can be picked out with relative ease, but to 'play' the classification as a virtuoso can take a lifetime of study and practice."
Most library researchers do not realize that, although the Library of Congress does not use the Dewey Decimal Classification to organize its book holdings, virtually all maintenance and updating of the DDC is performed here.
But if the Library of Congress has its own classification system, what is it doing with Dewey?
"Providing a national and international outreach to over 200,000 libraries in 135 countries throughout the world," said Mr. Smith.
"More libraries and research centers use the Dewey Decimal Classification than the Library's own classification system," he added. Many are small or medium-sized: public, school, academic and special libraries. Most major American university and research libraries, whose holdings come closer to matching the breadth and size of the Library's collections, prefer to use the LC classification to arrange and shelve their books.
There are some exceptions. In the United States, the University of Illinois and Duke and Northwestern universities use Dewey, as do large libraries in many other countries such as India, Australia and Canada. The United Kingdom is a mainstay of Dewey usage, and countries associated historically with it have continued to organize their libraries according to the DDC.
Melvil Dewey, founder of the first library school, inventor of his own phonetic spelling scheme (the vestiges of which have "mercifully" disappeared from the DDC, says Mr. Smith), cofounder of the Library Journal and other journals and two-time president of the American Library Association, devised his classification in 1873 for the Amherst College Library. It was first published in 1876.
Today, the system is published by Forest Press, a division of the OCLC Online Library Computer Center. Forest Press provides financial support for the editorial work carried on in the Decimal Classification Division. (Such work has been centered at the Library of Congress since 1923.)
The DDC is used by division classifiers to provide Dewey numbers for items being cataloged in the major languages of interest to most Dewey-using libraries: English, Spanish, Italian, French, German and some Chinese. Approximately two-thirds of all books cataloged by the Library are assigned Dewey numbers. These numbers are disseminated worldwide, primarily through the Library's MARC distribution services.
The notational design of DDC is deceptively simple. The fundamental arrangement in the DDC is by discipline, and then topic within discipline. A topic may appear in several places in the classification, depending on the viewpoint of the work. For example, a book on marriage may be classed in ethics, religion, sociology, law, medicine, music, etc., depending on the disciplinary focus.
All books are organized under 10 major classes (or areas of knowledge), each of which bears its own three-digit set of Arabic numerals. Religion is 200, for example; natural sciences and mathematics are grouped under 500, while literature and rhetoric fall under 800. These classes are further divided into 100 divisions and 1,000 sections, and then extended further by a decimal point and additional digits. Thus, under the main class 500, Natural Sciences and Mathematics, comes the discipline of Mathematics at 510. Calculus, an area within mathematics, is classed at 515, which is further subdivided into topics such as Differential Equations at 515.33.
This hierarchical method of classifying books allows libraries to group like works within a discipline and relate them to broader and narrower topics in the same discipline.
The classification has grown steadily since its first published version, which contained 44 pages and 926 classes. By the 20th edition, published in 1989, the publication had grown to four volumes with 3,344 pages. The 12th abridged edition was published in 1990 in one volume of 857 pages. New editions are published about every seven years; the 21st edition will be published in 1996, the 13th abridged edition in 1997. There is even an electronic version of the classification, Electronic Dewey, introduced by OCLC Forest Press in January 1993.
History: The Library of Congress considered the Dewey Decimal Classification for its collections in the late 1890s, when it became obvious that the existing system developed by Thomas Jefferson would no longer suffice. But after Mr. Dewey rejected the Library's suggested revisions to the DDC, the institution decided to develop its own classification system.
Rather than relying on the 10 main classes that form the DDC's primary structure, the Library of Congress Classification consists of 21 classes published in 48 volumes. The classes are designated by a capital letter (D-History; K-Law; N-Art; Q- Science, etc.). These are further divided into two or three letter subclasses (DC-History of France; KFG-Law of Georgia; NB- Sculpture; QK-Botany), with further arrangement by numbers to represent specific topics (DC203- Napoleon; NB1312-Equestrian statues; QK617-Mushrooms). It has taken staffers nearly 100 years to complete the basic system.
Approximately 5,000 new or changed class numbers are added annually. The system is enumerative: Library of Congress Classification makes explicit provision for a great number of topics.
'Where the Books Are': Since LC neither owns nor uses DDC to classify its books, why is the division located in the heart of the Cataloging Directorate's operations?
"To be where the books are," said Joan Mitchell, the new editor of the DDC. "We're constantly reviewing and considering expansions and revisions of numbers to cover new disciplines and subject areas. As human knowledge grows, so do the types and contents of the books that are published. The only way to be aware of and assess these changes is to review the current literature. The DDC is not an intellectual exercise; it's a living organism that must adapt to the changing world of knowledge manifested in published works."
Ms. Mitchell cited numerous changes to headings to the DDC over the years, all made in response to user needs and changes in knowledge and viewpoints. For example, in response to an explosive growth of literature in computer science, a new schedule for Dataprocessing/Computer Science was devised, quickly published separately in 1985 to meet user demand, and later included in the 1989 full edition. The Music (780) schedule was revised in the 20th (most recent) edition to remove Western bias and provide for new musical forms.
Both of these developments required the introduction of new notation and the reuse of some existing numbers. Such changes are made cautiously, because changes are costly to libraries and users.
Many changes can be accommodated within the existing structure, either by expanding or contracting the notation or changing the terminology.
"Over time, much of the terminology that was once considered standard becomes outdated or even offensive," Ms. Mitchell continued. "That's why we replaced the term 'Eskimo' with more specific terms such as 'Aleut' and 'Inuit,' the names preferred by the people themselves. We're constantly updating, correcting and adding terms to reflect changes in culture, political events and scientific and technical progress.
"We also want to introduce colloquial terms, which may vary from one country to another." She cited as an example the U.S. term "dropouts," whose British counterpart is "school leavers."
As editor of the 21st edition of DDC, Ms. Mitchell works with a team of three assistant editors and 10 classification specialists. The specialists apply numbers to records for books cataloged by the Library. The staff refers to a broad range of sources to identify and assess proposed changes to the system including specialists from other divisions in the Library. In addition to searching in-house data bases, they consult official publications and experts in appropriate fields. After conducting extensive in-house review, the division refers its suggested changes to the Decimal Classification Editorial Policy Committee (EPC), an international advisory committee whose members are appointed by OCLC Forest Press and the American Library Association. EPC also includes a representative from the Library of Congress.
After the committee approves, rejects or requests more information about proposed changes, OCLC Forest Press has the option of accepting or rejecting their recommendations. To date, all have been accepted.
"We invite and receive much feedback from users. Responding to users' needs is a high priority," said Ms. Mitchell. "Also, the DDC's inherent flexibility allows libraries to tailor the classification to suit their needs." Libraries may apply the numbers as specifically or as broadly as their local collection requires. In fact, the Decimal Classification Division "segments" the numbers applied to bibliographic records into logical groups to aid this process.
"Such adaptability is important, especially when you're developing one basic system to serve libraries of varying sizes in different countries," said Ms. Mitchell. "Options are provided in places where the English-language standard edition arrangement may not be optimal for the local collection. For example, various options are provided to highlight the literature of a specific country at a broader number. Such options facilitate international use."
Surprisingly, the DDC isn't just for libraries anymore.
The classification is not merely a way of assigning locational numbers to books, it is a logical system that can organize any number of topics within disciplines, moving from the broad, general categories, to the most specific.
The fact that the entire classification exists in electronic form makes new uses inside and outside of libraries feasible. "One could imagine using DDC to organize knowledge bases or provide a framework for accessing information over computer networks such as the Internet," Ms. Mitchell pointed out.
In short, the Dewey Decimal classification lives up to its motto by providing "numbers you can count on."
