Library Classification Systems: Subject

Within a library collection, materials are typically organized by subject. Items are assigned a call number based on their subject. Then sources are shelved by that call number so that anyone browsing the shelves will find most of the titles on a subject together.

There are 2 main classification systems that libraries can use to assign call numbers. These are Library of Congress and Dewey Decimal.

The examples below illustrate how the Library of Congress and Dewey Decimal classification systems are used to assign call numbers for the book, Battle in Seattle by Janet Thomas, published in 2000, about the demonstrations during the WTO summit in Seattle.

Library of Congress: Used in most college, university, and research libraries, including UTSA, because it handles large collections.
Dewey Decimal: Used in most public and school libraries because it is more effective for smaller collections.

For more information about these classification systems, follow the links below.

Library of Congress

Dewey Decimal

Superintendent of Documents (SuDocs) (for US government documents)

Finding Sections

1. Finding
2. Library Classification Systems: Citations
3. Reading Citations
4. Citation Exercise
5. Library Catalogs
6. Finding Exercise
7. Library Organization: Sections
★ Library Classification Systems: Subject