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Primary v. Secondary v. Tertiary Sources
Below are links leading to commonly defined distinctions between primary vs. secondary vs. tertiary sources. If you are working with a source type and unclear into which one or more categories that item falls, ask your Professor or a Librarian.
Some tricky elements among these distinctions can occur at times because:
Definitions vary depending on the research community one inhabits (e.g., social sciences vs. humanities vs. business research, etc.).
Across a broad sweep of history, there can be a tendency for what is clearly defined as a secondary source at one point in time (a 2017 journal article analyzing trade sanctions against Iran) to become over an even longer period of time, a primary source, depending upon how the source is used. Thus, in the year 2525, some future historian may treat that one time secondary academic journal source as a representative primary source for its time period.
With advent of easier forms of desktop publishing and digital reproduction (although true long before the Internet), it is possible for tertiary and secondary sources to contain reproductions of primary source materials (e.g., a sizable United Nations encyclopedia, a tertiary source, might contain a copy of relevant reproduced text from an international treaty, a primary source).
Here are links to definitions, with examples
Syracuse University Libraries Research Process Subject Guide - Primary v. Secondary Sources
Cornell University Library - Primary, Secondary, and Tertiary Sources: A Quick Guide
Online Dictionary of Library and Information Science by Joan M Reitz (ABC-CLIO)
Offers excellent definitions of primary source, secondary source, and tertiary source. Click on "p" "s" and "t," respectively, and scroll down to those definitions.
Questions you should ask of every source you find
- What is the publication/creation date?
- Does this time period meet your information need?
- When was the last update?
- Are all the links up-to-date ( for web resources)?
- Who is the author? What are her/his credentials?
- Has the author been cited in other sources?
- Who is publishing this information (individual, non-profit organization, commercial entity)?
- Do other sources contain the same information?
- Is evidence given to support the information?
- Are other sources cited?
- Is the site edited, or does it contain typographical errors (for web resources)?
- Who is the intended audience (students, researchers, trades people, children, adults)?
- Is this source appropriate for your needs and understanding of the topic?
Point of View (Bias)
- Does the source present the information from a particular bias or single viewpoint?
- Does the source contain assumptions not backed by research?
- Does the sponsoring organization or site have a stake in how information is presented?
- Does the information contain advertising?
Wikipedia and many other non-academic internet sources are good tools for presearch--finding out more about your topic--but - with marginal exceptions - they are not generally regarded as highly esteemed sources when conducting scholarly research. They would quite rarely be pointed toward in most published academic research as one's sole category of source material (although they certainly may be examined as primary sources themselves). Review of peer-reviewed/scholarly journal articles in your topic area will offer further evidence of the types and titles of source publications that are most often cited (e.g., a wide variety of peer-reviewed academic books and articles by others who research the United Nations).
Wikipedia, being an online encyclopedia,is much like most traditional encyclopedias, a tertiary source. These types of sources can be helpful in offering summaries and also at times by directing you to others forms of more primary, as well as secondary source, publications.