Types of Sources

Using Source Type to Evaluate Information

Information comes in all shapes, sizes and qualities. One way to differentiate and evaluate information is to categorize it by its source type. (Sources are also sometimes called resources or artifacts.)

Sometimes you will be asked to find specific types of sources to act as evidence supporting an argument or thesis statement in a research paper, such as when your professor asks you to find “two books and one web source” as part of your bibliography for an assignment. Identifying the type of source you’re using helps to illuminate other details about that source, including:

  • The intended audience
  • The scope of the information

It’s first helpful to consider how to differentiate between primary and secondary sources.

Primary and Secondary Sources

Primary sources are those created first-hand, providing direct evidence and information about a person, event or subject. Primary sources may include:

  • letters
  • notes
  • raw data
  • social media interactions
  • scientific papers reporting on experimental research

Secondary sources build on primary sources to describe, analyze, comment about or evaluate information relating to a person, event or subject. Secondary sources may include:

  • newspaper or journal articles
  • books
  • reviews (book reviews, movie reviews)
  • literature reviews

Other Ways to Define Sources: Source Types

After you have a better understanding of primary and secondary sources, you can apply that knowledge to other source types. It is difficult to capture all of the terms used to categorize source types, especially when you take into consideration that different disciplines use and interpret terms in different ways.

As long as you understand and appreciate that there are many different types of sources — and that these sources are becoming further complicated by physical (analog) and digital formats — you will be okay.

The terms serials and periodicals are often used interchangeably — depending on who you’re talking to — to describe the types of sources that are published serially (in a series) or periodically (with some regularity, whether daily, weekly, monthly, etc.).

For example, journals, magazines and newspapers are published on an ongoing basis. These source types differ in that they can be primary or secondary sources and in that they can be popularpeer-reviewed or scholarly, depending on the publisher.

Non-fiction books and eBooks are often secondary sources — an analysis or evaluation of primary sources on a specific subject by an author.

-content vs. container

-accessing eBooks at Sul Ross


Visual and audio materials include maps, photos, prints, graphic arts and original art as well as videos, films and digital recordings. Often, visual and audio materials are primary sources created at a specific time. These sources can provide rich context to significant events and provide insight into the ways people lived and viewed the world.

Often, archival material sources are primary sources. These include documents such as manuscripts, letters, diaries, legal and documents as well as visual and audio material as addressed above. Archival documents can be found in print, but are increasingly found digitized online.

Note: The Sul Ross Library houses the Archives of the Big Bend. Learn more about specific collections on the Archives’ website.

Government documents and reports usually include data, policies, statistics relating to specific matters relating to the functioning of government.