A primary source provides direct or firsthand evidence about an event, object, person or work of art. Generally, primary sources are contemporary to the events and people described and show minimal or no mediation between the document/artifact and its creator. Primary sources can be written and non-written, the latter including sound, picture, and artifact. Examples include:

• personal correspondence and diaries
• works of art and literature
• speeches and oral histories
• audio and video recordings
• photographs and posters
• newspaper ads and stories
• laws and legislative hearings
• census or demographic records
• plant and animal specimens
• coins and tools

Secondary sources contain information that has been interpreted, commented on, or analyzed.They are produced sometime after an event happens. History textbooks, dictionaries, encyclopedias, interpretive journal articles and monographs, and book reviews are all examples of secondary sources. Secondary sources are often based on primary sources.

Keep in mind that primary and secondary sources are not fixed categories. The use of evidence as a primary or secondary source hinges on the type of research you are conducting.

• For example, a history textbook is typically considered a secondary source if you are using it to learn about historical events. But the textbook is considered a primary source if you are doing educational research on how history textbooks have changed over time.
• Biographies often fall within both categories since primary sources were likely consulted heavily in the writing of a reliable account