Purpose:
- DDC: The DDC is a general classification system that can be applied to a wide range of subjects and types of materials, including books, journals, articles, and audiovisual materials. It is designed to provide a systematic and hierarchical organization of knowledge, allowing users to browse and find resources on a specific topic within a broader subject area.
- MeSH: MeSH is a controlled vocabulary and classification system specifically designed for indexing and searching biomedical and health-related information. It is used to index journal articles, books, reports, and other types of resources in the fields of medicine, health sciences, and related disciplines.
Structure:
- DDC: The DDC is a hierarchical classification system organized in ten main classes, each further divided into subclasses, sections, and subsections. Each item is assigned a unique decimal notation that represents its position in the hierarchy. For example, the DDC class for "Natural History" is 500, and the subclass for "Zoology" is 590.
- MeSH: MeSH uses a tree structure with controlled vocabulary terms arranged in a hierarchical fashion. Each term is assigned a unique MeSH ID and can be linked to related terms through broader, narrower, and related term relationships. This structure allows for precise indexing and searching of biomedical information.
Notation:
- DDC: The DDC uses a decimal notation system, with each class, subclass, section, and subsection denoted by a three-digit number. The decimal notation allows for easy expansion and interpolation of new subjects within the existing classification scheme.
- MeSH: MeSH uses alpha-numeric codes to identify its controlled vocabulary terms. Each term is assigned a unique code consisting of a letter followed by a number, such as "A01.166" for "Abdominal Pain."
Scope:
- DDC: The DDC covers a wide range of subjects across all disciplines, including science, technology, social sciences, humanities, arts, and more. It provides a broad overview of knowledge and is commonly used in general libraries and public libraries.
- MeSH: MeSH focuses specifically on biomedical and health-related information. It covers a vast range of medical concepts, diseases, drugs, organisms, and other biomedical topics. It is primarily used in medical libraries, hospitals, and other healthcare institutions.
Updating:
- DDC: The DDC is regularly updated and revised to keep pace with the evolving nature of knowledge. New editions are published periodically, typically every few years, to incorporate new subjects and changes in terminology.
- MeSH: MeSH is updated annually to ensure its currency and relevance in the rapidly evolving field of biomedical information. New terms are added, and existing terms are revised or removed based on changes in medical knowledge and research.
In summary, the Dewey Decimal Classification is a general classification system for organizing a wide range of subjects, while the MeSH Classification System is specifically designed for indexing and searching biomedical and health-related information. They differ in their purpose, structure, notation, scope, and frequency of updates.