Learn more about the Dewey Decimal Classification (DDC) and the DDC Summaries

The Dewey Decimal Classification (DDC) system is the world's most widely used library classification system. It is built on sound principles that make it ideal as a general knowledge organization tool.

At the broadest level, the DDC is divided into ten main classes, which together cover the entire world of knowledge.

The main structure of the DDC is presented in three summaries (outlines) of the Dewey Decimal Classification.

The first summary contains the ten main classes, providing a broad overview of the DDC:

Class Caption
000 Computer science, information & general works
100 Philosophy & psychology
200 Religion
300 Social sciences
400 Language
500 Science
600 Technology
700 Arts & recreation
800 Literature
900 History & geography

The three summaries provide an overview of the intellectual and notational structure of the DDC system, but they do not always reveal the full substance of what the numbers represent.

To understand the breadth of each number and caption, one must consult the DDC classification schedules.

A variety of educational resources is also available.

Try it out

ResearchWorks provides access to the DDC Summaries in two ways:

  • in Microsoft Excel format
  • as a PDF document with additional descriptive text

Please note that your use of the DDC Summaries is governed by Terms and Conditions in addition to the ResearchWorks license.

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