Primary and secondary sources: how to tell them apart and analyze them

What makes a source primary or secondary

The question to ask is: how close was the creator to the event? A primary source is first-hand evidence from the time. A secondary source is second-hand: it looks back, explains and draws conclusions, usually using many primary sources.

A third category, tertiary sources, collects and summarizes secondary sources. Encyclopedias, dictionaries and many textbooks fall here. They are useful for getting started, but historians build arguments from primary and secondary sources.

Examples of each

Here are common examples, using well-known documents:

• Primary: the Declaration of Independence (1776), a document written and signed by the people who made the decision it announces.
• Primary: Anne Frank's diary, written from 1942 to 1944 while her family hid from the Nazis in Amsterdam.
• Primary: Dorothea Lange's 1936 photograph Migrant Mother, taken during the Great Depression.
• Primary: Abraham Lincoln's Gettysburg Address, a soldier's letter home, a census record, a newspaper report written the day after an event.
• Primary: physical objects from the time, such as tools, clothing, coins or buildings.
• Secondary: a history textbook chapter on the American Revolution.
• Secondary: a biography of Lincoln written in the twenty-first century.
• Secondary: a documentary film or a historian's journal article analyzing the Great Depression.

It depends on your question

Whether a source is primary or secondary depends on what you are studying. A history textbook from 1955 is a secondary source about the Civil War. But if your question is how American schools taught the Civil War in the 1950s, that same textbook is a primary source, because it is evidence from the time you are studying.

Similarly, a memoir written decades after an event is a primary source because the author lived through it, but memory fades and changes, so it needs more checking than a diary written the same day. Being primary does not make a source true, and being secondary does not make it less valuable.

How to analyze a source: four habits

Historians and many history classes use four habits of reading a source. They are often called sourcing, contextualization, close reading and corroboration:

• Sourcing: before reading closely, look at who created it, when, where, for whom and why. A general's report to his superiors and a private soldier's letter home may describe the same battle very differently.
• Contextualization: what was happening at the time and place it was made? A speech given during a war, an election or an economic crisis is shaped by that moment.
• Close reading: what does the source actually say, and how does it say it? Notice word choice, tone, what is emphasized and what is left out.
• Corroboration: compare it with other sources. Where do they agree and where do they differ? Agreement among independent sources makes a claim more reliable; disagreement tells you to dig further.

Worked example: analyzing a newspaper report

Imagine a newspaper article from 1914 in a country that has just entered World War I, reporting that the nation's army won an important battle and that enemy troops fled in panic.

Sourcing: a newspaper written for the home public, during wartime, when governments often censored news. Context: early in the war, when each side expected a quick victory and wanted to keep up morale. Close reading: words like "glorious" and "fled in panic" suggest a goal of encouraging readers, not only informing them. Corroboration: compare it with the other side's reports, soldiers' letters and later historians' accounts of the battle.

A careful conclusion is not "this source is biased, so it is useless." A better one is: "This source is weak evidence for what happened in the battle, but strong evidence for what the public was being told and how the government wanted the war to be seen." Every source is reliable for some questions and not others.

Point of view, purpose and audience

Every source has a point of view. That is not a flaw to hide; it is information to use. Many classes use a short checklist, especially for document-based questions:

• Historical situation: the events and conditions surrounding the source.
• Intended audience: who was meant to read, see or hear it.
• Purpose: why it was made, such as to inform, persuade, record or entertain.
• Point of view: the creator's position, experience and interests, and how they shape the content.

Common mistakes

Students often lose points on source questions by:

• Assuming primary sources are always accurate. A witness can be mistaken, limited in what they saw, or trying to persuade.
• Dismissing a source as "biased" without explaining how the bias affects what it can tell you.
• Summarizing a source without analyzing it. Say what it shows and how reliable it is for your question.
• Labeling sources by format alone. A website or a video can be primary (a recording of a speech) or secondary (a lecture about it).
• Using one source as if it settled the question. Corroborate with at least one other.

How to practise

Pick any document, photograph or object and write four short sentences: one each for sourcing, context, close reading and corroboration. Free collections such as the Library of Congress and the US National Archives offer thousands of digitized primary sources, from letters to photographs.

To check your labeling, write down your research question first, then decide for each source whether it comes from the time and people you are studying or looks back at them. If you cannot say why a source is primary or secondary for your question, revisit the definitions above.