MHS Library: Primary Sources

Primary sources are the raw materials of historical research - they are the documents or artifacts closest to the topic of investigation.  They are immediate, first-hand accounts of a topic, from people who had a direct connection with it. Primary sources can include:

• Texts of laws and other original documents.
• Newspaper reports, by reporters who witnessed an event or who quote people who did.
• Speeches, diaries, letters and interviews - what the people involved said or wrote.
• Original research.
• Datasets, survey data, such as census or economic statistics.
• Photographs, video, or audio that capture an event.

Often they are created during the time period which is being studied (correspondence, diaries, newspapers, government documents, art) but they can also be produced later by eyewitnesses or participants (memoirs, oral histories). You may find primary sources in their original format (usually in an archive) or reproduced in a variety of ways: books, microfilm, digital, etc.

Secondary Sources are one step removed from primary sources, though they often quote or otherwise use primary sources. They can cover the same topic, but add a layer of interpretation and analysis. Secondary sources can include:

• Most books about a topic.
• Analysis or interpretation of data.
• Scholarly or other articles about a topic, especially by people not directly involved.
• Documentaries (though they often include photos or video portions that can be considered primary sources).

When is a Primary Source a Secondary Source?

Whether something is a primary or secondary source often depends upon the topic and its use.

A biology textbook would be considered a secondary source if in the field of biology, since it describes and interprets the science but makes no original contribution to it.

On the other hand, if the topic is science education and the history of textbooks, textbooks could be used a primary sources to look at how they have changed over time.

Tertiary Sources draw on information already contained in primary sources (original documents or research reports) and secondary sources (books, magazines, newspapers, TV broadcasts, and other published sources that are matters of public record).

Also called reference works, these sources give an overview of information gathered from primary and secondary sources but do not provide original interpretations or analysis. Examples include: 

• Dictionaries
• Bibliographies 
• Encyclopedias, including Wikipedia

Tertiary sources do not provide original insights or analyses. Instead, they collect, index, and provide an overview of primary and secondary sources. This means that while you might use them to learn more about a topic you’re new to, you’re unlikely to cite them in your paper.

Many of our Library Subscription Databases include both Primary and Secondary Sources.  See instructions next to the database link for how to limit searches to Primary Source materials. 

There are also countless primary sources digitized on the internet - libraries, museums and archives all have content available online. A few examples are linked below.