Primary sources provide firsthand evidence of a fact and do not provide any outside interpretation. Just about anything can be a primary source.
Primary sources may be something created or documented at the time of an event, including original research (usually published in scholarly journals), diaries, photographs, and conference proceedings. It may also be something documented at a later time, such as autobiographies, memoirs, and oral histories.
This is in contrast to secondary sources, which interpret or analyze information. Secondary sources are often based on primary sources and include textbooks and some scholarly journal articles, books, and reference books.
Another type of source is called a tertiary source. Tertiary sources are publications such as encyclopedias or other compendia that mainly summarize secondary sources. This includes Wikipedia.com and other encyclopedias. Your own research papers and projects are probably tertiary sources!
Defining a source as primary, secondary, or tertiary depends on the context. In other words, how you are using the material will determine if a source is considered to be a primary source.
This example is from the University of Maryland:
A magazine article reporting on recent studies linking the reduction of energy consumption to the compact fluorescent light bulb would be a secondary source. A research article or study proving this would be a primary source. However, if you were studying how compact fluorescent light bulbs are presented in the popular media, the magazine article could be considered a primary source.
Remember, just because a piece of information is from a primary source does not mean it is scholarly! Our guide Primary vs. Secondary Sources will help you identify primary sources in various disciplines or subjects.