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6.5: Types of Sources

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    You probably know by now that if you cite Wikipedia as an authoritative source, the wrath of your professor shall be visited upon you. Why is it that even the most informative Wikipedia articles are still often considered illegitimate? And what are good sources to use? The table below summarizes types of secondary sources in four tiers. All sources have their legitimate uses, but the top-tier ones are preferable for citation.

    A lineup of different fruits, each cut in half, with a measuring tape stretched beneath all of them.
    Just as different fruits have different internal structures, different kinds of sources have different characteristics and uses.
    Photo by Deon Black on Unsplash under the Unsplash License.

    Types of Sources

    Tier Type Content Uses How to find them
    1 Peer-reviewed academic publications Rigorous research and analysis Provide strong evidence for claims and references to other high-quality sources Google Scholar, library catalogs, and academic article databases
    2 Reports, articles, and books from credible non-academic sources Well researched and even-handed descriptions of an event or state of the world Initial research on events or trends not yet analyzed in the academic literature; may reference important Tier 1 sources Websites of relevant agencies, Google searches using (site: *.gov or site: *.org), academic article databases
    3 Short pieces from newspapers or credible websites Simple reporting of events, research findings, or policy changes Often point to useful Tier 2 or Tier 1 sources, may provide a factoid or two not found anywhere else Strategic Google searches or article databases including newspapers and magazines
    4 Agenda-driven or uncertain pieces Mostly opinion, varying in thoughtfulness and credibility May represent a particular position within a debate; more often provide keywords and clues about higher quality sources Non-specific Google searches

    Tier 1: Peer-reviewed academic publications

    These are sources from the mainstream academic literature: books and scholarly articles. Academic books generally fall into three categories: (1) textbooks written with students in mind, (2) monographs which give an extended report on a large research project, and (3) edited volumes in which each chapter is authored by different people. Scholarly articles appear in academic journals, which are published multiple times a year in order to share the latest research findings with scholars in the field. They’re usually sponsored by some academic society. To get published, these articles and books had to earn favorable anonymous evaluations by qualified scholars. Who are the experts writing, reviewing, and editing these scholarly publications? Your professors. I describe this process below. Learning how to read and use these sources is a fundamental part of being a college student.

    Tier 2: Reports, articles, and books from credible non-academic sources

    Some events and trends are too recent to appear in Tier 1 sources. Also, Tier 1 sources tend to be highly specific, and sometimes you need a more general perspective on a topic. Thus, Tier 2 sources can provide quality information that is more accessible to non-academics. There are three main categories. First, official reports from government agencies or major international institutions like the World Bank or the United Nations; these institutions generally have research departments staffed with qualified experts who seek to provide rigorous, even-handed information to decision-makers. Second, feature articles from major newspapers and magazines like The New York Times, The Wall Street Journal, The London Times, or The Economist are based on original reporting by experienced journalists (not press releases) and are typically 1500+ words in length. Third, there are some great books from non-academic presses that cite their sources; they’re often written by journalists. All three of these sources are generally well-researched descriptions of an event or state of the world, undertaken by credentialed experts who generally seek to be even-handed. It is still up to you to judge their credibility. Your instructors and campus librarians can advise you on which sources in this category have the most credibility.

    Tier 3. Short pieces from periodicals or credible websites

    A step below the well-developed reports and feature articles that make up Tier 2 are the short tidbits that one finds in newspapers and magazines or credible websites. How short is a short news article? Usually, they’re just a couple paragraphs or less, and they’re often reporting on just one thing: an event, an interesting research finding, or a policy change. They don’t take extensive research and analysis to write, and many just summarize a press release written and distributed by an organization or business. They may describe things like corporate mergers, newly discovered diet-health links, or important school-funding legislation. You may want to cite Tier 3 sources in your paper if they provide an important factoid or two that isn’t provided by a higher-tier piece, but if the Tier 3 article describes a particular study or academic expert, your best bet is to find the journal article or book it is reporting on and use that Tier 1 source instead. If the article mentions which journal the study was published in, you can go right to that journal through your library website. Sometimes you can find the original journal article by putting the scholar’s name and some keywords into Google Scholar.

    What counts as a credible website in this tier? You may need some guidance from instructors or librarians, but you can learn a lot by examining the person or organization providing the information (look for an “About” link). For example, if the organization is clearly agenda-driven or not up-front about its aims and/or funding sources, then it definitely isn’t something you want to cite as a neutral authority. Also look for signs of expertise. A tidbit about a medical research finding written by someone with a science background carries more weight than the same topic written by a policy analyst. These sources are sometimes uncertain, which is all the more reason to follow the trail to a Tier 1 or Tier 2 source whenever possible.

    Tier 4. Agenda-driven or pieces from unknown sources

    This tier is essentially everything else, including Wikipedia.4 These types of sources—especially Wikipedia—can be hugely helpful in identifying interesting topics, positions within a debate, keywords to search on, and, sometimes, higher-tier sources on the topic. They often play a critically important role in the early part of the research process, but they generally aren’t (and shouldn’t be) cited in the final paper. Throwing some keywords into Google and seeing what you get is a fine way to get started, but don’t stop there. Start a list of the people, organizations, sources, and keywords that seem most relevant to your topic. For example, suppose you’ve been assigned a research paper about the impact of linen production and trade on the ancient world. A quick Google search reveals that (1) linen comes from the flax plant, (2) the scientific name for flax is Linum usitatissimum, (3) Egypt dominated linen production at the height of its empire, and (4) Alex J. Warden published a book about ancient linen trade in 1867. Similarly, you found some useful search terms to try instead of “ancient world” (antiquity, Egyptian empire, ancient Egypt, ancient Mediterranean) and some generalizations for linen (fabric, textiles, or weaving). Now you’ve got a lot to work with as you tap into the library catalog and academic article databases.

    Practice Exercise \(\PageIndex{1}\)

    Choose a topic that interests you and find one source related to it in each of the four tiers. What could you learn from each source?  What are the limitations of each source?

    Attributions

    Adapted by Anna Mills from Writing in College: From Competence to Excellence by Amy Guptill, published by Open SUNY Textbooks, licensed CC BY NC SA 4.0.


    6.5: Types of Sources is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.