A primary source is a document or other piece of evidence written or created during the time being studied, or by one of the persons or organizations directly involved with the event. Some examples of primary sources include:
Secondary sources are those that describe, analyze, interpret, or review your primary source. Often, secondary sources are written years after the fact, and can thus take into consideration other events, or otherwise place a primary source in historical context.
Note: Science disciplines may define "primary" and "secondary" sources differently. For example, in the sciences, original research is considered a primary source. This guide addresses social sciences and humanities definitions.
When doing historical research, primary sources can give you a more personal view of the period or event you are researching. While secondary sources (sources created after the fact) can be useful for looking back at an event or time more critically through the lens of "what happened next," primary sources can tell you how the people at the time you are studying felt about the events happening around them.
Depending on the discipline you are working in, primary sources can take on a variety of forms. For disciplines where new data is generated, the academic articles or reports that contain this data are considered primary sources. If you generate your own data, that is also a primary source.
For other disciplines, primary sources in newspapers, archives and special collections, or databases that specialize in a given topic (i.e. Historical Statistics of the United States) might be more relevant. A few examples are pulled out below:
Discover documents from over 500 years of world history through digitized, text-searchable primary sources.
Search 14 major historical U.S. newspapers collectively or individually. Time period covered ranges from 1764 up through 4 years ago.
Access a wide range of media and collections in the Media Center, including maps, movies and TV shows, educational films, audio books, music, the Microforms Collection, and audiovisual equipment.
Generally, secondary sources include the following:
You can locate secondary sources in Quick Search, library catalogs, and scholarly indexes. Use keyword searches to begin, and use words that describe elements of your specific topic. You can consult with a reference librarian to identify and search relevant catalogs and indexes, or try one of these: