Primary sources are historical records. This is in contrast to secondary sources, which are retrospective accounts. For example, The Declaration of Independence is a primary source, while a biography of Thomas Jefferson is a secondary source.
- Primary Source: A fundamental, authoritative document related to a subject of inquiry, used in the preparation of a later derivative work. Primary sources may include letters, diaries, and other personal papers, photographs, interviews and transcripts, government and historical records, newspaper clippings, and other original sources.
- Secondary Source: A document concerning a particular subject of inquiry which is derived from, or based on, study and analysis of original source materials.
Materials such as encyclopedias that compile information from primary and secondary sources may be called tertiary sources. Catalogs like the Guide to Reference Sources could even be called quaternary sources.
Teaching people how to distinguish these source types is a common component of library instruction. Usually due to specific school assignment requirements, librarians often educate users on identifying and locating primary and secondary sources. "Where are the primary sources shelved?" can be a recurring reference desk question.
- Primary, Secondary, and Tertiary Sources Definitions and charts