Introduction: The Universal Decimal Classification (UDC) is a comprehensive and versatile system for organizing and classifying knowledge. Developed in the late 19th century and continuously updated since then, the UDC provides a logical and hierarchical framework that encompasses a wide range of subjects, making it a valuable tool for libraries, information centers, and researchers worldwide. By assigning unique decimal numbers to various topics, the UDC allows for efficient retrieval and navigation of information, facilitating the sharing and dissemination of knowledge across different disciplines and cultures. It’s adaptability and international recognition have made the UDC an indispensable resource for organizing information in an ever-expanding world of knowledge.
The Universal Decimal Classification (UDC) Scheme
The Universal Decimal Classification (UDC) scheme of classification was developed in the year 1895 by the Belgium Barrister Paul Otlet and Nobel Prize winner Henri La Fountaine. The UDC is peculiar in the sense that it consists of a combination of both enumerative and faceted characters of the schemes. Hence, it is designated as an Almost-Faceted Scheme of Classification. The UDC is derived from DDC as universal since it encompasses the whole field of knowledge. It is the multi-lingual general classification tool for organizing all kinds of recorded knowledge in the library. It is an international classification system mainly developed for the purpose of indexing and arranging an enormous card bibliography, which not only includes books but also all kinds of documents, periodical articles, patents, trade catalogues, abstracts, and other micro documents in more than 28 different international languages.
The International Institute of Bibliography (IIB) was organized under the aegis of an International Conference on Bibliography held in Brussels in 1895. One of the main objectives was to devise a scheme of classification for its use in indexing world literature. The existing schemes of classification were found inadequate for the purpose; therefore, it is an international extension and adaptation of the DDC, initially by two Belgians, Paul Otlet and Henry La Fontaine. The first edition appeared in French in 1905 as Manual du Repertoire Bibliographique Universel, which has 33,000 sub-divisions. The second edition was also published in French, containing 70,000 sub-divisions. The third edition was published in German in 7 volumes of tables and three volumes of alphabetic index containing 140,000 sub-divisions. Complete editions have also appeared in French, Spanish, and Japanese languages. The publication of the English translation was started in 1943 and entitled “Universal Decimal Classification,” and was designated as the fourth international edition. The British Standards Institution published the third revised edition of the abridged English Edition in 1961. The Abridged edition of the UDC has been published in 13 different languages.
Purpose of UDC
The Universal Decimal Classification (UDC) serves multiple purposes that contribute to the efficient organization and retrieval of information. These purposes include:
- UDC provides a systematic method for arranging books on library shelves. Assigning unique decimal numbers to various subjects allows for logical and consistent placement of books, enabling users to easily locate relevant materials within a library’s collection.
- UDC facilitates the arrangement of sub-titles or subject headings in catalogues and printed bibliographies. By utilizing the decimal classification system, UDC enables the grouping related subjects and provides a standardized way to present information about books and other resources, making it easier for users to identify relevant materials.
- One of the primary purposes of UDC is to classify recorded knowledge. It offers a comprehensive and hierarchical framework that covers a wide range of subjects and disciplines. By assigning unique numbers to specific topics, UDC allows for the systematic organization of knowledge, enabling users to explore related subjects and discover new areas of interest.
- UDC plays a crucial role in information retrieval by providing a means to locate documents. Each subject in UDC is assigned a specific code, allowing users to search for and retrieve documents based on their subject classification. This systematic approach saves time and effort, as users can quickly access relevant information without having to rely solely on text-based searches.
The Universal Decimal Classification serves as a valuable tool for organizing and accessing information across various domains, contributing to the effective management and dissemination of knowledge.
Features of UDC
The Universal Decimal Classification (UDC) has several distinct features contributing to its practicality, flexibility, and international standardization. These features include:
- UDC is designed to meet the practical needs of organizing pamphlets, reports, and periodical literature. Rather than being based solely on theoretical principles, it focuses on the demands of real-world information management.
- UDC is considered the first Analytico-synthetic classification scheme. It combines analytical (breaking down subjects into specific topics) and synthetic (bringing together related topics) elements, providing a balanced approach to classifying knowledge.
- UDC emphasizes achieving co-extensive class numbers, which means providing detailed specifications within classes. This focus on granularity allows for precise subject representation, enabling users to locate specific information more effectively.
- UDC avoids the limitations of private classification schemes by offering a standardized and comprehensive system that covers all disciplines. It can be utilized in any library, providing a consistent framework for organizing information.
- UDC is a unified and integrated whole, offering a general classification scheme rather than a collection of specialized classifications. It provides a broad structure that can accommodate various subjects and disciplines.
- UDC reflects exhaustive enumeration in its schedule, ensuring comprehensive coverage of topics. It also incorporates provisions for synthesis or coordination, enabling the classification of interdisciplinary subjects and facilitating cross-disciplinary exploration.
- UDC allows for adjustments to meet specific needs, as the citation order within a class permits alternative treatment of subjects. This flexibility enables customization while maintaining consistency with the overall system.
- UDC employs synthetic devices, such as the colon (:), to facilitate the coordination of concepts. These devices minimize the rigidity of an enumerated classification scheme, providing more flexibility in classifying related topics.
- UDC is maintained and revised by an international body, ensuring continuous development and up-to-date relevance. The active cooperation of its users guarantees that the system remains current and responsive to evolving information needs.
- UDC employs a comprehensive vocabulary of terms, which aids in indexing and information retrieval. Standardized terminology enhances consistency and facilitates precise subject representation within the classification system.
Principles of UDC:
- It is a classification in the strict sense depending on the analysis of an idea and content so that the related concepts and groups of concepts are brought together and are arbitrary or haphazard systemization of alphabetical and other arrangements are avoided.
- It is a universal classification system for which an attempt has been made to include in it every field of knowledge not as a patchwork of isolates, self-sufficient specialists grouping but as an integrated pattern and correlated subjects.
- It is constructed on the principles of proceeding from general to the more particular revision of the whole human knowledge into ten main branches; each further subdivided decimally to the required degree.
- It is a practical system for the retrieval of information in which the order of subjects is not of much more importance than the provision for detailed specifications.
- It also accepts the principles of mutually exclusive classes, collection of related subjects, and consistency of approach.
- It has tried to remove national and racial basis to some extent by removing these factors and performing common facets.
- Its notation consists of Indo-Arabic numerals used decimally, allowing infinite hospitality and social sciences.
- It employs certain notational techniques by which it is possible to link simple main class or other main numbers with auxiliaries indicating place, time, and similar commands used for categories.
UDC Notations and Symbols:
The UDC is based on the Dewey Decimal Classification’s outline and notational base. The basic notation of UDC consists of Indo-Arabic numerals 0-9 used decimally, the different mathematical symbols, and punctuation marks that have converted its notation into a mixed notation. The naught and decimal point have been omitted for convenience and have been implied. The numbers indicate 0, 1, 2, 3, 4, 5—-. UDC uses single-digit numbers, and every digit is a significant one. However, the use of different signs and symbols has added qualities to the notation of UDC.
|+||Plus||Connection of non-consecutive numbers|
|/||Stoke||Connection of consecutive numbers|
|[ ]||Square Brackets||Relation (Subordinate)|
|(=)||Brackets Equals||Race and Nationality|
|” “||Inverted Commas||Time|
|A-Z||A to Z||Individual Sub-divisions|
|–||Hyphen||Special Analytical numbers|
|.00||Point Double Zero||Point of View|
|.0||Point Naught||Special Analytical numbers|
Structure of UDC
The whole universe of knowledge in UDC is divided into two categories.
- Systematic Tables- The systematic tables are also called schedules which give the notational number of all basic classes from 0-9. The general order and nomenclature of the main table are the same as DDC. The whole universe of knowledge is divided into ten main branches denoted by decimal fractions and Indo-Arabic numerals. UDC uses one-digit numbers for the main class. The main class numbers and their subdivisions are divided by a continuous extension of the decimal fraction on the principle of proceeding from general to specific. The practice of DDC to use a dot after every three digits has been retained in UDC. In UDC, the 4th class is kept vacant for future subjects.
Ten main Classes of UDC
|0||Science and Knowledge. Organization. Computer Science. Information Science. Documentation. Librarianship. Institutions. Publications|
|5||Mathematics. Natural Sciences|
|6||Applied Sciences. Medicine, Technology|
|7||The Arts. Entertainment. Sport|
Revision Policy of UDC:
The Scheme is revised and updated from time to time by the International Federation for Information and Documentation (FID). The development and maintenance of UDC is achieved by FID at Hague through its ultimate coordinating body i.e., Central Classification Committee. This committee is assisted in its work, directly or indirectly, by the National Committees, Special Subject Committees in each Country, and International Subject Committees. Thus, it follows a decentralized procedure for the revision of the UDC. The revision is done in the following three ways:
- Extension of topics by more detailed sub-divisions.
- Minor changes in the existing class numbers of sub-divisions.
- Starvation Policy introduced by Donker Duyvis. This policy assumes a fair state of collection and opportunity for re-classification. Donker Duyvis used the unused notation in the dynamic and rapidly changing the subject.
If the users of the UDC want to suggest amendments or extensions to the schedules, they have to suggest the same to a National Body in their respective Countries. The changes in the UDC are communicated to its users by a half-yearly bulletin titled Extensions and Corrections to UDC. From the end of 1991, responsibility and updating were assumed by a new organization, the UDC Consortium (UDCC), which publishes the bulletin, Extensions, and Corrections of the UDC.
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