What it is: Library of Congress Subject Headings began in 1909 as the Subject Headings Used in the Dictionary Catalogues of the Library of Congress and was originally created only for the Library of Congress's collection. The list is large and addresses a great number of topic, but is deceptive because of the specificity of the list to the LC collection itself. The LC may not have topics that would be needed in another library, based on their collection. However, it has been widely adopted as the universal tool for libraries everywhere (Intner & Weihs, 2015).
How it Works: There are eight basic principles of the LCSH:
Headings based on literary warrant
Complex headings are pre-coordinated
Subdivisions must be added to main headings in a pre-determined order
No synonyms
Headings are equal in the content being describes and are directly entered
The scope of a meaning is equal and/or matching
For example, you would not look for "dogs" under "Animals-Dogs", but would look directly for "Dogs."
(Intner & Weihs, 2015)
Advantages:
Chosen authority of a large percentage of librarians and provides a built in cohort (Intner & Weihs, 2015).
Workshops and training widely available to understand and continually develop skills that will help provide a quality catalog to users (Intner & Weihs, 2015).
Authority files are availble online for free for the general public (Kaplan & Riedling, 2006).
Disadvantages:
Specific to LC Collection
Some headings may be too narrow for another collection
Technical vocabulary may be hard for users to understand and hinder navigation of the catalog
Revisions of headings that were outdated took a long time to be revised. There are a number of headings that may still need to be changed due to changes in language, or offensive meanings. However, in recent years, this has begun to change and the LC is striving to remedy this.
(Intner & Weihs, 2015)
Additional Resources for Library of Congress Subject Headings