Dewey Decimal Classification
[1] Originally described in a 44-page pamphlet, it has been expanded to multiple volumes and revised through 23 major editions, the latest printed in 2011.
OCLC, a non-profit cooperative that serves libraries, currently maintains the system and licenses online access to WebDewey, a continuously updated version for catalogers.
Libraries previously had given books permanent shelf locations that were related to the order of acquisition rather than topic.
The classification's notation makes use of three-digit numbers for main classes, with fractional decimals allowing expansion for further detail.
Numbers are flexible to the degree that they can be expanded in linear fashion to cover special aspects of general subjects.
The number makes it possible to find any book and to return it to its proper place on the library shelves.
[14] Library stacks were generally closed to all but the most privileged patrons, so shelf browsing was not considered of importance.
The use of the Dewey Decimal system increased during the early 20th century as librarians were convinced of the advantages of relative positioning and of open shelf access for patrons.
[16] In response to the needs of smaller libraries which were finding the expanded classification schedules difficult to use, in 1894, the first abridged edition of the Dewey Decimal system was produced.
Charles Ammi Cutter published the Expansive Classification in 1882, with initial encouragement from Melvil Dewey.
Dewey gave permission for the creation of a version intended for bibliographies, and also for its translation into French.
[17] By the 14th edition in 1942, the Dewey Decimal Classification index was over 1,900 pages in length and was published in two volumes.
Beginning in 1922, the Lake Placid Club Educational Foundation, a not-for-profit organization founded by Melvil Dewey, managed administrative affairs.
[32] On the death of May Seymour, Dewey conveyed the "copyrights and control of all editions" to the Lake Placid Club Educational Foundation, a non-profit chartered in 1922.
[33] The Online Computer Library Center of Dublin, Ohio, U.S., acquired the trademark and copyrights associated with the Dewey Decimal Classification system when it bought Forest Press in 1988.
Their work is reviewed by the Decimal Classification Editorial Policy Committee, a ten-member international board which meets twice each year.
[36] In 2017 the editorial staff announced that the English edition of DDC will no longer be printed, in favor of using the frequently updated WebDewey.
[39] In addition to the full version, a single-volume abridged edition designed for libraries with 20,000 titles or fewer has been made available since 1895.
[40] The Dewey Decimal Classification organizes library materials by discipline or field of study.
Tables cover commonly used elements such as geographical and temporal aspects, language, and bibliographic forms.
[50] In 1932, topics relating to homosexuality were first added to the system under 132 (mental derangements) and 159.9 (abnormal psychology).
In 1996, homosexuality was added to 306.7 (sexual relations); this remains the preferred location in the current edition.
The entire 200 section has remained largely unchanged since DDC 1, since restructuring would pose a significant amount of work for existing libraries.
The motivation for this change is ideological rather than technical, as appending significant figures can add space as needed.
[54] It has also been argued by Hope A. Olson[55] that the placement of topics related to women shows implicit bias, but this has been simpler to address than the religion schema.
