When writing a research paper, you may be asked to use primary sources. Another assignment may require use of both primary and secondary sources. What are these types of sources? How do you distinguish between the two?
Primary sources are original materials such as diaries, interviews, letters, original documents, photographs, and patents. They are original items on which other research materials (such as articles and reports) are based. Primary sources are especially valuable in that they originated during the time period being studied and have not been filtered by interpretation or evaluation. Secondary sources are materials such as journal articles, encyclopedias, biographies, and essays that describe, interpret, analyze and evaluate primary sources.
Sometimes it may be difficult to identify a source as primary or secondary. For example, newspaper articles can be either a primary or secondary source: a newspaper article from 1871 reporting on the Great Chicago Fire would be a primary source; but an article from 2004 that describes popular myths about that fire would be a secondary source. If you are struggling to define a resource, a helpful rule of thumb is to think of primary sources as “first-hand” materials and secondary sources as “second-hand” accounts.
For more information on primary and secondary sources, see the Online Study in Information Literacy.