Dewey Decimal Classification and Fundamental Laws Governing Knowledge

by Moya K. Mason


Throughout history, attempts were made to record culture by people who saw the importance of preserving the knowledge and documents of their own civilization. The degree and nature of this activity varied as did the cultures, and ranged from simple cave paintings to more sophisticated systems of classification seen in ancient institutions, such as the Alexandrian Museum and Library. Cultural relevancies and temporal developments have always been deciding factors in determining the types of subjects compiled on tablets, scrolls, and books. How they were interpreted and the fashion in which they were classified changed over time, but some things may be said in general about the historical development of knowledge and how two of its principle characteristics make classification quite easy under the Dewey Decimal system. Specifically, this essay will look at how the Dewey Decimal Classification system hospitably integrates the fundamental fact that the universe of knowledge is forever expanding. Also discussed will be the historically acceptable fashion of setting knowledge down in an hierarchical order and its relevancy within the Dewey Decimal System.

Origins of the Dewey Decimal Classification System

Melvil Dewey was born on December 10, 1851 in Adams Center in New York. His extensive diaries show that he was filled with hopes, fears, and dreams, and by the time he was eighteen had made the decision to "... devote my life to Education" (Wiegand 1996,12). While at Amherst College, born was his belief that free schools and free libraries were the right of everyone (Wiegand 1996,19). He believed that reading was the cornerstone of a good education, and that well-stocked free public libraries constituted one of the great engines of education (Dewey 1930). Dewey decided to spend his life working for educational reforms to help improve lives (Wiegand 1998,5). Writing in his diary, he explained his decision to dedicate his life to reform:

I always realized that out of a score of things that had greatly attracted me, I could do only one with one life and so I determined that my highest usefulness would be to stimulate others to take up the work . . . seeking out and inspiring and guiding others to do the work for which my one life did not give time (Dewey).

He also had strong views on the power of books and how reading can change lives. As Dewey was finishing his bachelor's degree, he took a part-time job at the college library to help pay his tuition (Wiegand 1998,5). He began to read the books in the library, often reading each one twice and taking notes on most (Wiegand 1998,5). Dewey knew that the library's resources were rarely used. Few students bothered with the library. Amherst professors expected their students to buy the books required for each class and reading assignments came directly from them (Sherman 2009,27). There was no reason to use the library. At the time, most libraries were small and had few books because they were so expensive. When a new book was introduced to the collection, the librarian would simply shelve the book wherever there was space. You could easily find a book of poetry shelved next to one about geography or a book about the Peloponnesian Wars.

By the mid-19th century, things began to change for libraries. Books were getting cheaper and libraries were expanding. There were a number of classification systems, but they all had inherent problems. Dewey was in the right place at the right time. He had realized early on in his life the important role libraries could play in educating people and decided to focus his career on making libraries easier to use (Wiegand 1998,5). As more and more books came into the Amherst library, Dewey knew the old way of doing things couldn't work for the long term. A new classification system was needed. Dewey decided to embark on a journey to discover a better way to catalogue the universe of knowledge, looking for a system that would make using libraries easier, one that would offer patrons better access to its books. For months, he analyzed the strengths and weaknesses of every classification system he could, reading everything on the subject of book arrangement (Dewey 1920). He finally realized that he would have to develop something different. But what? While sitting in church one Sunday listening to a long sermon by the President of Amherst College, William Augustus Stearns, he had what he called a Eureka moment:(1)

I dreamed night and day that there must be a satisfactory solution . . . one Sunday during a sermon the solution flashed over me so that I jumped in my seat and came very near shouting, "Eureka!" Use decimals to number a classification of all human knowledge in print. (Dewey 1920).

He first published his classification system in 1876, and started reclassifying Amherst's collection using it. Although it has expanded and seen many changes, it has survived and flourished. What is the DDC20 and how does it organize the universe of knowledge?

Melvil Dewey
Melvil Dewey

An Overview of the Dewey Decimal Classification System

Principally, classification systems were used to develop order out of the ever-expanding world of knowledge. More specifically, Wynar states: "the ultimate aim of any classification system is to lead the patron to the items required" (Wynar 1992,317). That was the dream of Melvil Dewey. His dream was to play a role in educating the masses, and fulfilled this desire by developing a system that puts related topics in an hierarchical order from general to as specific as needed. His was a faceted system, which developed facets or the characteristics of division. The facets are mutually exclusive and exhaustive, so that every topic may be accounted for (Wynar 1992,320-21). Some are very specific, while others are more general and can be applied to many subjects. Most importantly, Dewey's system depends upon recurring facets, such as Periods (Wynar 1992,320). He did not classify under subjects. Instead, his hierarchical system organized the universe of knowledge into "traditional academic disciplines or fields of study" (DDC20 1989,xxvi).

He used ten such fields, numbering them from 000 to 900, with the first digit representing its main class. Each main class was then divided into ten separate divisions, with numbers running from zero to nine and each division divided into sections or subdivisions, also using the zero to nine numerical sequence. An example may help to illustrate the system. Using the number 931, one can say that the nine represents the main class, the three represents the separate division, and the one, a distinct section (DDC20 1989,xxviii). To the right of the third number goes a decimal point, which can theoretically continue to divide the number by ten to classify very specific topics. Dewey's most important contribution to the field of classification is that by using hierarchical divisions, which are subdivided with the decimal system, division can continue indefinitely, allowing for new areas to be added (Wynar 1992,328). By using the decimal system, Dewey allowed for pure notation and relatively close shelf proximity for books on related topics (Wynar 1992,327). Since there is no "single place for a given subject, ... the Relative Index assembles the disciplinary aspects of a subject in one place" (DDC20 1989,xxvii). For example, if you look up "Birth", you will find notations as varied as 392.12 and 808.80354 under the heading. The Relative Index is an integral part of the system.

The Principles

Dewey's system made relative location possible and did away with problems of rigidly fixed location methods (Evans & Heft 1994,431-33). Books could be shelved anywhere a librarian wanted them without altering their order. This was extremely progressive since knowledge is always growing. The continually-increasing amount of knowledge is the foremost consideration when employing a catalogue system, because it is the one constant that can be relied upon (Abrera 1974,30). Examples would be the fast growing fields of nanotechnology and biotechnology. Also, Sociology used to be 301, now it is 301-307 (DDC20 1989,xiii). It needed a broader range to reflect new societal concerns. The DDC20 can incorporate any number of new areas of study, since its structure of decimals allows for infinite additional notations. It does so with 'hospitality,' having the ability to include any additions easily and quickly (Abrera 1974,33). The DDC20 is very adaptable. As Phyllis A. Richmond states:

The system must be hospitable to all knowledge, including things that never were, such as phlogiston; things that never shall be, like utopias; and things that are impossible, like the square root of minus one (Bengtson & Hill 1990,18).

The common procedure of beginning with general knowledge and working towards specific in an hierarchical system of ordering can be traced primarily to Aristotle, who identified classes and sub classes. By arranging them in an hierarchy, he was able to see relationships between objects and concepts (Abrera 1974,21 29). He moved from the general to the specific, or from the extension to the intention. This had great possibilities for library classification and is actually what lies behind Dewey's entire system. As Wynar stresses, "[n]o matter what scheme is chosen, or how large the library, the purpose of classification is to bring related items together in a helpful sequence from the general to the specific" (Wynar 1992,317). For example, 700 represents the Arts, while 702 is Miscellany of fine and decorative arts, and 735.21 is Sculpture circa 1400-1799. With Dewey, one can get as specific as needed, just by adding another number. Remember to always make natural and logical decisions in sub-dividing when using hierarchical classifications (Wynar 1992,317).

In Conclusion

The DDC20 has had a long history because it is a valuable tool in the classification of knowledge, but like most things has good and bad points. It is very adaptable for small libraries because "it stresses hierarchies of subject matter" (Wynar 1992,323), but its numbers can become long and unwieldy, making them difficult to remember, and even more difficult to fit on book spines (Evans & Heft 1994,433). Wynar also makes the point that although Dewey is adaptable enough to accept new topic areas, there is all the work and expense associated with making those changes in a library setting (Wynar 1992,325). Even so, it is flexible enough to make it the only choice for many institutions. The DDC is used extensively throughout the world in 135 countries, and can be found in over 200,000 libraries. The Dewey Decimal Classification (DDC) system has been owned by OCLC since 1988; as of May 2011, it is in its 23rd edition.

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1Melvil Dewey always contended that his classification system was unique. For a different assessment on the historiography on the origins of the scheme, see Wayne A. Wiegand's The Amherst Method: The Origins of the Dewey Decimal Classification Scheme.

Reference List

Abrera, J.B. 1974. Traditional Classification: Characteristics, Uses and Problems. Drexel Library Quarterly, Vol. 10, No. 4, pp. 21-36.

Bengtson, B. and J.S. Hill. 1990. Classification of Library Materials. New York: Schuman Neal.

Dewey, Melvil. Speech given to the Lake Placid Education Foundation (LPEF) Trustees on July 28, 1930.

Dewey, Melvil. Decimal Classification Beginning. Library Journal, Vol. 45, February 15, 1920, pp. 151-152.

Dewey Decimal Classification. 20th. ed. 1989. Albany: Forest Press.

Evans, G.E. and S. Heft, 1994. Introduction to Technical Services. Englewood, Co.: Libraries Unlimited.

Sherman, Jill. 2009. Melvil Dewey: Library Genius. Edina, MN: Abdo Publishing Company.

Wiegand, W.A. 1996. Irrepressible Reformer: A Biography of Melvil Dewey. Chicago: ALA Editions.

Wiegand, W.A. 1998. The "Amherst Method:" The Origins of the Dewey Decimal Classification Scheme. Libraries & Culture, Vol. 33, No. 2, Spring 1998.

Wynar, B.S. 1992. Introduction to Cataloguing and Classification. 8th ed. Littleton, Co.: Libraries Unlimited.

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