Dewey Decimal Classification (DDC)

 

INTRODUCTION

The Dewey Decimal Classification (DDC), often referred to as the Dewey Decimal System, is one of the most enduring and widely used library classification systems in the world. It provides a structured way to organize books and other library materials based on subject matter in a systematic and logical manner, making it easier for users to locate resources in libraries. DDC arranges knowledge into ten main classes, each represented by a three-digit number. These classes are further divided into more specific topics using decimal notation. The Dewey Decimal Classification (DDC) is a proprietary library classification system developed by Melvil Dewey. It was first published in the United States in 1876. It is used in approximately 200,000 libraries in over 135 countries.

HISTORY AND DEVELOPMENT

The DDC was conceived by Melvil Dewey, an American librarian, in 1873 while he was a student at Amherst College. The first edition was published anonymously in 1876 as a 44-page pamphlet titled "A Classification and Subject Index for Cataloguing and Arranging the Books and Pamphlets of a Library." Dewey's innovative system was revolutionary because it used decimal numbers to categorize knowledge hierarchically, allowing for infinite expansion as new subjects emerged. 

Over the years, the DDC has evolved significantly. It has gone through 23 major editions, with the most recent print edition released in 2011. Today, it is maintained by OCLC (Online Computer Library Center), a nonprofit cooperative that serves libraries globally. An online version called WebDewey is continuously updated to reflect changes in knowledge and terminology. 

PURPOSE OF DDC

The primary purpose of the DDC is to organize library materials in a systematic and accessible way. By assigning a unique numerical classification to each item, libraries can ensure that books on similar subjects are shelved together, making it easier for patrons to browse and locate information. This logical arrangement enhances the discoverability of resources and optimizes the efficiency of library operations.

OBJECTIVES OF DDC

The main objectives of the Dewey Decimal Classification are:

• To organize knowledge logically
• To facilitate the easy retrieval of information
• To allow infinite expansion using decimal notation
• To provide uniformity and consistency in library arrangement

STRUCTURE OF DEWEY DECIMAL CLASSIFICATION 

At its core, the DDC organizes knowledge into ten main classes, each representing a broad discipline or field of study. These classes are divided into divisions and sections, using a decimal-based notation for increasing specificity. This hierarchical structure allows for precise classification while accommodating growth in any subject area.

DDC is based on a hierarchical structure:

• Main Classes (000–900)
• Divisions (10 divisions within each class)
• Sections (10 sections within each division)

Each level adds greater subject specificity.

The Ten Main Classes of DDC

The DDC categorizes all knowledge into ten main classes, each represented by a three-digit number. These main classes cover a broad spectrum of subjects, from philosophy and religion to science, technology, and history.

Here are the ten main classes:

000 (000–099) - Computer Science, Information & General Works: This class includes encyclopedias, bibliographies, computer science, and journalism.

Example: 004.6 - Local Area Networks (LAN)

100 (100–199) - Philosophy & Psychology: This covers metaphysics, epistemology, ethics, logic, and various schools of psychology.

Example: 150 - Psychology

200 (200–299) - Religion: This class encompasses world religions, mythology, and theology, with a strong focus on Christianity.

Example: 294.3 - Buddhism

300 (300–399) - Social Sciences: This includes sociology, economics, law, political science, education, and social welfare.

Example: 330 - Economics

400 (400–499) - Language: This covers linguistics, specific languages, dictionaries, and grammar.

Example: 420 - English Language

500 (500–599) - Science: This class includes mathematics, astronomy, physics, chemistry, biology, geology, and botany.

Example: 570 - Biology

600 (600–699) - Technology: This covers applied sciences, medicine, engineering, agriculture, home economics, and manufacturing.

Example: 610 - Medicine & Health

700 (700–799) - Arts & Recreation: This includes fine arts, music, performing arts, sports, and recreation.

Example: 796.357 - Baseball

800 (800–899) - Literature: This class covers literature of specific languages, poetry, drama, fiction, essays, and rhetoric.

Example: 823 - English Fiction

900 (900–999) - History & Geography: This includes geography, travel, biography, and history of specific regions and periods.

Example: 940 - History of Europe

Divisions and Sections of DDC

Each main class is further subdivided. For instance, the 500s (Natural sciences and mathematics) break down into divisions like 510 (Mathematics), 520 (Astronomy), and so on. These divisions are then segmented into sections, such as 595 (Other invertebrates) within the 590s (Zoological sciences).

Divisions and Sections: Examples

Example 1: Science (500)

• 500 – Natural Sciences
• 510 – Mathematics
• 516 – Geometry
• 516.3 – Analytic Geometry

Example 2: Technology (600)

• 600 – Technology
• 630 – Agriculture
• 636 – Animal Husbandry
• 636.7 – Dogs

Example 3: Literature (800)

• 800 – Literature
• 820 – English Literature
• 823 – English Fiction
• 823.914 – Contemporary English Fiction