What is library classification?
A library classification is a system of coding and organizing library materials according to their subject, and allocating a "call number" to that information resource.
Similar to classification systems used in biology - such as Linnaean taxonomy - bibliographic classification systems group entities that are similar together typically arranged in a hierarchical tree structure (assuming a non-faceted system of course).
Classification of a piece of work consists of two steps. Firstly the 'aboutness' of the material is ascertained. Next, a call number based on the classification system will be assigned to the work using the notation of the system.
Types of classification
There are many systems of library classification, which generally can be divided into three types depending on how they are used. In terms of functionality, classification systems are often described as:
- Enumerative - which produces an alphabetical list of subject headings, and assign numbers to each heading in alphabetical order
- Hierarchical - which divides subjects hierarchically, from most general to most specific
- Faceted (or analytico-synthetic) - which divides subjects into mutually exclusive orthogonal facets
There are few wholly enumerative systems or faceted library classification systems, as most systems are a blend of two or more types. The most common classification systems, Library of Congress Classification (LCC) and Dewey Decimal Classification (DDC), are essentially enumerative, though with some hierarchical and faceted elements.
The first true faceted library classification system was the Colon classification of the mathematician and librarian S. R. Ranganathan. |
