Is a textbook a secondary or tertiary source?

Textbooks are usually considered tertiary sources because they synthesize a wide range of secondary and primary sources to provide an introductory overview of a subject.

Can I cite Wikipedia in an academic essay?

While Wikipedia is a tertiary source, most professors discourage citing it directly. Instead, use Wikipedia to find the primary and secondary sources listed in its references section.

When should I avoid using tertiary sources?

Avoid using tertiary sources as your main evidence in upper-level research papers. They lack the specific detail and original analysis required for advanced academic arguments.

What Are Tertiary Sources?

Explainer4 min·Updated May 2024

Definition of Tertiary Sources

Tertiary sources are publications that index, abstract, organize, or compile information from primary and secondary sources. Their main purpose is to provide a broad overview of a topic or to help researchers locate more detailed information. They do not contain original research or new analysis but instead summarize established knowledge.

Primary vs. Secondary vs. Tertiary Sources

Dimension	Primary Sources	Secondary Sources	Tertiary Sources
Goal	Provide raw data	Analyze primary data	Organize information
Content	Original research	Interpretation	Summaries and lists
Tone	Eyewitness/Direct	Analytical/Critical	Objective/General
Evidence	Direct evidence	Evaluative evidence	Background info
Structure	Unstructured/Raw	Argumentative	Encyclopedic/Indexed
Example	Lab results	Journal article	Encyclopedia

Understanding the Role of Tertiary Sources

Tertiary sources act as the third layer of information. If a primary source is a diary entry from a soldier (raw data) and a secondary source is a history book analyzing that diary (interpretation), the tertiary source is the encyclopedia entry about the war that mentions the book and the soldier. These sources are designed for accessibility and breadth rather than depth. Common examples include dictionaries, almanacs, bibliographies, and fact books. They are essential for gaining a 'big picture' understanding of a complex topic before diving into specific scholarly debates.

Examples in Research Contexts

Example

To understand how these sources differ in a real-world essay, consider the topic of Climate Change:

* **Primary Source:** A dataset of global temperature readings collected by NASA satellites over 10 years.
* **Secondary Source:** A peer-reviewed article in *Nature* analyzing that NASA data to prove a specific trend in melting ice caps.
* **Tertiary Source:** A Wikipedia page or a textbook chapter on 'Global Warming' that summarizes the findings of the *Nature* article and lists the NASA dataset as a reference.

In this chain, the tertiary source is the most removed from the actual event but the easiest to read for a beginner.

When to Use Tertiary Sources

Use tertiary sources during the pre-research phase of your essay. They are excellent for finding keywords, identifying major figures in a field, and understanding general timelines. However, once you begin writing your body paragraphs, replace tertiary information with citations from secondary or primary sources to increase your paper's authority.

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