Primary sources are original, uninterpreted information.  Scholars analyze primary sources in order to answer research questions. Examples of primary sources vary by discipline.

Examples in the humanities:

• a novel
• a painting
• a theatre performance

Examples in the social sciences:

• a political, social, or economic theory
• a dataset
• the results of an experiment published in a peer-reviewed journal

Example in the sciences:

• the results of an experiment published in a peer-reviewed journal

Primary sources in philosophy are most frequently the works of the philosopher him/herself, though letters, lectures, and contemporary criticism may also be useful primary materials depending on your topic.