liminfoDewey Classification
Free reference guide: Dewey Classification
About Dewey Classification
The Dewey Decimal Classification Reference is a practical guide to the DDC system used in libraries worldwide, covering all 10 main classes from 000 (Generalities/Computer Science) through 900 (History/Geography). Each main class entry includes its primary divisions and notable subdivisions, such as 005.133 for specific programming languages, 006.3 for artificial intelligence, 332.6 for investment, and 895.7 for Korean literature, making it easy to locate the correct classification number for any subject.
Beyond the main classes, the reference provides detailed coverage of DDC classification rules including the hierarchical number building system (3-digit base with decimal subdivisions), standard subdivisions from Table 1 (-01 philosophy, -03 dictionaries, -09 historical treatment), geographic area numbers from Table 2 (-519 Korea, -52 Japan, -73 United States), and literature subdivision tables (Table 3) for poetry, drama, fiction, and essays. It also explains complex subject classification rules and the principle of classifying by most specific subject.
The reference includes practical information for library professionals: Cutter number assignment for author notation in call numbers, DDC edition history from Melvil Dewey's 1876 first edition through the current 23rd edition and WebDewey online tool, comparison between DDC and other major classification systems (LCC, UDC, KDC), and hands-on classification practice examples for materials like Python programming books, Korean economic history, and modern Korean fiction.
Key Features
- All 10 DDC main classes (000-900) with primary divisions and key subdivisions for computer science, economics, medicine, and more
- Number building rules explaining the 3-digit hierarchical structure with decimal subdivision notation (e.g., 512.5 for linear algebra)
- Standard subdivisions (Table 1) reference: -01 philosophy, -02 miscellany, -03 dictionaries, -05 serials, -07 education, -09 history
- Geographic areas (Table 2) with country codes including Korea (-519), Japan (-52), China (-51), United States (-73)
- Literature subdivision tables (Table 3) for poetry (-1), drama (-2), fiction (-3), essays (-4) with worked examples
- Cutter number assignment method for constructing complete call numbers with DDC classification + author notation
- DDC vs KDC vs LCC comparison showing structural differences and international usage context
- Practical classification exercises: Python programming (005.133), Korean economic history (330.95195), Korean fiction (895.735)
Frequently Asked Questions
What are the 10 main classes of the Dewey Decimal Classification?
000 Generalities (Computer science, information), 100 Philosophy (including psychology), 200 Religion, 300 Social Sciences (politics, economics, law, education), 400 Language (linguistics), 500 Natural Sciences (math, physics, chemistry, biology), 600 Technology (medicine, engineering, agriculture), 700 Arts (architecture, music, recreation), 800 Literature, and 900 History (geography, biography).
How does the DDC number building system work?
DDC uses a hierarchical 3-digit base structure where each digit adds specificity: 500 represents Natural Sciences, 510 narrows to Mathematics, 512 to Algebra, and 512.5 to Linear Algebra. The decimal point separates the base number from further subdivisions. Standard subdivisions from Table 1 can be appended to add aspects like -03 for dictionaries or -09 for historical treatment.
What standard subdivisions are available in DDC?
Table 1 standard subdivisions include: -01 (philosophy and theory), -02 (miscellany), -03 (dictionaries and encyclopedias), -05 (serial publications), -07 (education and research), and -09 (history and geographic treatment). These can generally be added to any DDC number to indicate the form or approach of a work.
How does DDC handle geographic classification?
Table 2 provides geographic area numbers that can be combined with base classification numbers. Key codes include -1 (Canada), -2 (United Kingdom), -51 (China), -519 (Korea), -52 (Japan), and -73 (United States). For example, Korean economic history would be classified as 330.95195, combining economics (330) with the Korean geographic notation.
How does DDC compare with KDC (Korean Decimal Classification)?
DDC and KDC share the same decimal structure but differ in some main class assignments. For example, DDC assigns 400 to Language while KDC assigns 700. The key difference is that KDC provides more detailed subdivisions for Korean-related materials, making it better suited for Korean library collections while DDC offers greater international universality with usage in over 200 countries.
What is a Cutter number and how is it assigned?
A Cutter number is an author notation added after the DDC classification number to create a unique call number for each item. It is derived from the Cutter table based on the author's last name. For example, a call number might be 005.133 K56 2024, where 005.133 is the DDC number for programming languages, K56 is the Cutter number for the author, and 2024 is the publication year.
What are the basic DDC classification principles?
Three fundamental principles guide DDC classification: (1) Subject over form, meaning content determines classification rather than physical format; (2) Interdisciplinary works go to the most useful class, prioritizing the field where the work has the greatest practical application; (3) The principle of least change, maintaining existing classification decisions where possible to ensure catalog stability.
Does this reference include classification practice examples?
Yes, the reference provides worked examples: a Python programming introduction is classified at 005.133 (specific programming languages), Korean economic history at 330.95195 (economics + Korea geographic notation), and modern Korean fiction at 895.735 (Korean literature 895.7 + fiction subdivision -3 from Table 3 + modern period notation 5).