Historians use different types of sources to make sense of the past. Variety is the spice of life, but it can be more than a little mind-boggling to keep them straight. If you're not sure what sources are for, or why we use them in AP US History, you are in the right place.
Read on for everything you need to know about sources for the AP US History exam and research papers!
Note: This article is going to use examples from AP US History. If you'd like an article with AP World History examples, click here!
What Is A Source?
This article assumes that you are familiar with the different types of historical sources and their uses. I will do a brief overview in this section, but I have a more comprehensive guide to different types of historical sources. It's a great resource if you're brand new to historical sources or if you're feeling a little rusty. You can view that guide here.
In brief, historians use sources to make sense of the past. This includes determining the facts of what happened in history. It also includes making meaning of history. For example, in AP US History you will make several kinds of connections between events and periods. For example, you may examine how one event caused other events to happen. You may also look at how two time periods are similar or different. Professional and amateur historians use a similar process.
These arguments must have evidence to back them up. Otherwise, they are works of fiction or propaganda.
There are different kinds of evidence, which historians refer to as sources. In AP classes, you may hear the term "document" or "stimulus" used instead of source. For our purposes, these words all mean the same thing. I will use source for clarity in this resource.
Finally, remember that there is some blur between categories. Some sources are clearly tertiary, and others are muddier. I have included examples here that I think best represent this type of source. I've also noted where you may need to use your best judgement.
What is a Tertiary Source?
The Basics
Tertiary sources summarize the factual details of history. They are created by researching primary and secondary sources. Then, the writer determines which facts and interpretations are generally accepted.
The biggest difference between secondary and tertiary source is the goal. A secondary source presents a historical argument. A tertiary source presents the basic facts of an event. This may include the significance of the event or it's connection to other events, as currently understood by historians. But a tertiary source isn't trying to present new research or advance its own argument.
"Tertiary" is a fancy way of saying third. Tertiary sources summarize primary and secondary sources. These other sources generally need to be created before they can be summarized. Therefore, tertiary sources are third in line. They are also the furthest removed from the actual events and scholarship.
Examples
All of the following can be tertiary sources. I've included an example in parentheses that's relevant to the AP US History curriculum.
- Encyclopedia articles (Cahokia on Wikipedia)
- Textbooks (The American Yawp)
- Bibliographies and Annotated Bibliographies (Explanation and Examples)
- AI-Generated Summaries
Limitations of Tertiary Sources
Limitation 1: Trust, But Verify.
Tertiary sources are best used to gather basic facts on a topic.
But, like all sources, you can trust those facts more when other sources confirm your findings. In theory, the authors of the tertiary source are doing some of this work for you. However, errors and "errors" can exist in tertiary sources.
Limitation 1: Not Free From Bias.
Tertiary sources also vary widely in quality.
Some tertiary sources are written by experts in a field. Those experts often cite sources and get other experts to check their work. This is generally true for textbooks and courses.
Open-source resources, like Wikipedia, use a different approach. They allow anyone to add, edit, and publicly critique information. They also allow people to add citations and additional reference materials. This means that errors can be identified and corrected by ordinary people. There are pros and cons to this approach compared to traditional methods.
But there are many tertiary sources that don't do any of these things. That's not always bad, and it doesn't always mean that something is amiss. It is worth investigating where that information comes from and getting multiple opinions. (Yes, that does include this site.)
Finally, some sources are actively hiding bias by presenting it as facts. However, if only one sides facts are presented, this is not a purely factual view of the issue. Similarly, bad actors sometimes assert their opinions using the language of facts. Be particularly wary of overly emotional or hyperbolic words.
Tertiary Sources in AP US History
In AP US History, you have to learn to do the work that a historian does.
This includes all sorts of fun things!
- Develop arguments that show causation, change over time, and similarities between historical events.
- Use evidence to prove your arguments are based in history and logical.
- Analyze the background of your text to strengthen your argument.
- Cite the sources you've used to develop your arguments.
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