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Primary, Secondary and Tertiary Sources for Research

What is a Primary Source?

A primary source is a record of a person, event, or occurrence that was created by an eye-witness or participant's version of an event. A primary source is a document or physical object which was written or created during the time under study.  According to the Library of Congress, "Primary sources are the raw materials of history — original documents and objects which were created at the time under study. They are different from secondary sources, accounts or interpretations of events created by someone without firsthand experience."  Types of primary sources include:
memoirs and diaries              government documents                      personal narrative

 letters                                         autobiographies                                    oral histories
 interviews                                  news film footage                                 journal articles with original research results
 manuscripts                             original maps                                        newspaper articles (from the time of the event)
 archival records                       sound recordings and movies      
 speeches                                  works of literature ( poetry, fiction)                                                                                  
 Use these terms as search terms in the library catalog and in library databases to access primary sources. 

What is a Secondary Source?

Secondary sources are created by persons who were not direct participants in an event. The author of a  secondary source interprets, explains and analyzes primary sources not personally witnessed or participated in by the author. Secondary sources are one or more steps removed from the event.  Secondary sources can be found in books, journals, or Internet resources. Secondary sources include sources with published scholarship on a subject, rather than supplementary material found in dictionaries or encyclopedias.  Supplementary materials are often referred to as tertiary sources.  Types of secondary sources include:                    

                         biographies                           newspaper articles on events after the fact               journal review articles
                         literary criticism                     book, art, and theatre reviews                                      literature reviews
                         textbooks                                magazine articles                                                           atlases                                                     

Use these terms as search terms in the library catalog and in library databases to facilitate access to secondary sources.

What is a Tertiary Source?

A tertiary source presents summaries or short versions of materials, usually with references back to the primary and/or secondary sources. They are useful supplementary sources which can be used  to look up facts or get a general overview of a topic.  Types of tertiary sources include:

                                dictionaries                       textbooks (may also be secondary)                 almanacs
                                encyclopedias                  directories                                                             handbooks 
                                guidebooks                       compilations                                                        indexes
                                abstracts                    bibliographies                                                                                                  
Use these terms as search terms in the library catalog and in library databases  to access tertiary sources.

Examples of Primary, Secondary, and Tertiary Sources


                        Primary Source

                 Secondary Source

         Tertiary Source

Art and Architecture

Painting by Van Gogh

Article reviewing the artistic significance of the  painting

Art Encyclopedia

Chemistry/Life Sciences

Einstein's 1912 manuscript on the special theory of relativity

Biography of  Einstein's life

Dictionary on Theory of Relativity

Engineering/Physical Sciences

Patent filed in U. S. Patent Office

Article discussing the usefulness of patents

Encylopedia of  Inventions


Letters by Theodore Roosevelt

Web site on the history of the family of Theodore Roosevelt

Almanac of American Presidents


Novel ,The Grapes of Wrath  by John Steinbeck

Magazine article reviewing the novel, The Grapes of Wrath

Encyclopedia of American Literature

Performing Arts

Copy of an original movie

Biography of the director

Handbook of Movies

Instructional Video

This video from Nova Southeastern University outlines what primary and secondary sources are and how users can tell the difference between the two. Focuses mainly on research articles. 4.56 minutes long.