Categorizing Sources

In order to determine which information sources best meet your research needs, it is necessary to understand the kind of information generally offered by different categories of sources.

One such category is "primary" vs. "secondary" sources.

When you make distinctions between primary and secondary sources, you are relating the information itself to the context in which it was created. Noting the relationship between creation and context helps us understand the “big picture” in which information operates, and helps us figure out which information we can depend on.

Primary Sources

Primary information sources are firsthand materials in their original form. Examples include:

Eyewitness reports (photographs, interviews)
Memoirs, diaries, oral histories, correspondence
Literary work (novels, plays, poems)
Artwork
Testimony (such as Congressional hearings)
Documentary films
Data, statistics, census reports
Social Media: Tweets, texts, status updates, original blogs

Primary sources often enable the researcher to experience the flavor of the original event or information, rather than relying upon someone else’s interpretation.

Photograph: Protesters with Causa Justa / Just Cause speak on the steps of San Francisco City Hall for a "Families Belong Together" rally. One holds a sign reading "Las Familias Pertenecen Juntas"

Eyewitness photograph: Protesters speak on the steps of San Francisco City Hall for a "Families Belong Together" rally.

Secondary Sources

Secondary information sources are those that gather, analyze, interpret, or repackage information from primary sources and/or other secondary sources. The information comes to us secondhand. Examples include:

Nonfiction books (that interpret real life events)
Magazine articles
Reviews, criticism
An article or website that synthesizes a number of sources for a new understanding of an event
Encyclopedias, including Wikipedia
Social Media: Pins on Pinterest, re-tweets, shared posts or links to other content

Secondary sources can provide valuable interpretation or historical context, provided the sources are trustworthy.

Cover of nonfiction book, "World of Walls: The Structure, Roles, and Effectiveness of Separation Barriers"

Nonfiction book analyzing the consequences of the construction of physical and virtual walls.

Text: Categorizing Sources adapted from "Primary, Secondary & Tertiary Sources" by Teaching & Learning, Ohio State University Libraries, licensed under CC BY 4.0

Photograph: "Families Belong Together SF march" by Pax Ahimsa Gethen is licensed under CC BY-SA 4.0

Book cover: "World of Walls: The Structure, Roles and Effectiveness of Separation Barriers" by Said Saddiki is licensed under CC BY 4.0