Primary, Secondary, and Tertiary Sources
Identifying the kind of source you are using is crucial to understanding both how to evaluate the source and how to use it in your research.
Primary sources are original sources of information that drives other research projects. Primary sources typically include documents like poems, diaries, court records, interviews, and oral history projects. Primary materials also include research results generated by experiments – including surveys, fieldwork, or data sets – which are eventually published as journal articles. Primary sources have not been interpreted, analyzed, or tabulated; they are raw reflections of the speaker or researchers' experiences. In the library, you can find primary sources in these databases and by searching for diaries, journals, or interviews in the Iona University Libraries' book collection.
Secondary sources describe or analyze the primary sources. Examples of secondary sources include dictionaries, encyclopedias, textbooks, books, and articles that interpret or review research works. Peer-reviewed publications generally fall into this category.
Tertiary sources list, compile, digest, or index primary or secondary sources. Indexes, handbooks, digests, and almanacs generally fall into this category.
To determine the type of source you are working with, consider the following contextual clues and publication details:
Timing of the event recorded - If the article was composed close to the time of the event recorded, it is likely a primary material. For instance, a letter written by a soldier during the Vietnam War is primary material, as is an article written in the newspaper or a soldier's letter home during the Civil War. However, an article written in 2022 analyzing the results of the battle at Gettysburg is secondary material.
Rhetorical aim of the written item - Often, an item that is written with a persuasive or analytical aim is secondary material. These materials have digested and interpreted the event, instead of reporting on it.
Context of the researching scholar - Primary materials for a critic studying the literature of the Civil War are different from primary materials for a historian studying Civil War prisons. The critic's primary materials are the poems, stories, and films of the era. The research scientist's primary materials would be the diaries and writings of enslaved families.
Adapted from University of Wisconsin-Stevens Point University Library
Methods for Evaluating Sources
Regardless of the type of resource you are examining - books, articles, social media posts, or AI-generated text - always evaluate the accuracy and reliability of the information you find before using it for your research. The CARDS method is one evaluative tool that allows you to make an informed decision about using a resource to further your own research.
Consider the following when determining the quality of an article or source:
C - Credibility:
- Is the author, publisher, or sponsor of the information evident? What are their credentials, reputation, education, or affiliations?
- Is there an "About Us" or "Contact Us" link? Besides an email address, is there a phone number or postal address to contact for more information?
If it's a book or article, what else has the author published? Does the reference have a bibliography? Is the information still valid today?
A - Accuracy:
- Do you see errors on the page (spelling, grammar, facts)? Errors like these not only indicate a lack of quality control (including a lack of peer-review) but can produce inaccuracies in the information.
- Do they cite the sources of their information?
R - Reliability:
- Is the source objective or does it advocate a certain point of view? Be strategic in this decision: objective sources allow you to foster a broader sense of a topic, while more persuasive pieces can dislodge details and nuances about your topic.
- Is the information free of advertising or clearly separated from it? If you are writing about Hurricane Katrina it is certainly interesting to read what BP said about the ensuing oil spills, but consider balancing that piece with a scientific perspective not funded by BP.
D - Date:
- Can you find the copyright date or the date when it was written or last revised?
- Do any statistics, graphs, or charts clearly state by whom and when the data was collected?
Are there links that no longer work? This indicates the site is not being meaningfully maintained and the information may be outdated.
S - Source:
- Is the information based on primary or secondary sources?
- Are there links to other sources that would score high in this CARDS evaluation or are more scholarly? Research is not quick but save yourself some time by using sources that connect you to other scholarly sources in the bibliography.
Despite this discussion of library resources, you might find your research requires more internet research than library research. Perhaps your topic is quite new and peer-reviewed articles have yet to be published, or you are being asked to analyze a company based on their public internet presence. Mike Caufield’s SIFT technique for source evaluation provides a reflective and thorough heuristic for evaluating internet sources.
Image Credit: Mike Caulfield, 2019. https://hapgood.us/2019/06/19/sift-the-four-moves/ All SIFT information on this page is adapted from his materials with a CC BY 4.0 license.
S – Stop
The SIFT method recommends two different crucial stopping points in your internet research:
When you first encounter a website or internet source, stop and consider:
- Do you know this source?
- Is this source reputable?
Are the claims on this website reputable to the best of your current knowledge?
If you can’t answer these questions, approach the source cautiously as you move through the other SIFT steps.
As you move through each step, stop and consider:
- What is my purpose for seeking this information out? Am I doing a quick scan of internet sources to understand the internet discourse of the day, or am I doing deep academic work? Both are useful kinds of research but involve a different set of questions and practices. The first involves a shallow scan across different sources, the second requires a deeper investigation of each figure, quote, etc.
Stop throughout your work to avoid falling into the proverbial internet rabbit hole, forgetting what you were researching in the first place.
I – Investigate the Source
This practice largely overlaps with evaluating a source and/or author’s credibility in the CARDS method. Take a minute or two to deduce:
- Who is the author? What are their credentials? What have they previously written on this topic?
- What is this source? Is it a newspaper, a blog, or a news aggregator website? Where does this source derive funding?
F – Find Better Coverage
Read laterally across the internet and library resources about this topic.
If you are writing about the prevalence of CTE in former NFL players, do not solely rely on a press release from the NFL about the topic. You can certainly use NFL statements, but be sure to read across medical journals, newspaper sources, and peer-reviewed research articles about CTE before completely forming your research argument around one source.
T – Trace Claims, Quotes, and Media Back to Original Context
Tracing involves pulling apart a resource for claims, quotes, images, videos, etc., and finding the original source. Think of this as swimming upstream, potentially to a better source. To trace:
- Click on any links to see what sources are being used to construct an argument. Are these sources reputable? Are these sources news aggregators? If a new item, is the source reputable?
- Check sources in the bibliography if present. Are those sources more academic than the source you are evaluating? Feel empowered to ditch your original source and move on to the linked source.
- Reverse image search photos used in the source.
- Search for the original full video of any embedded media. Did the source cut or manipulate the video? Did the article accurately summarize the video? If not, you can deduce the bias of the article and use it accordingly in your own research.
Note the internet address domain in this search string: "climate change" site:gov. This asks the search engine to limit it's search to .gov sites for research about climate change from American government agencies. Using domain searching is a kind of evaluation tool: rather than opening up the search to commercial entities that might support untested or unscientific approaches to climate change that further their business interests, this search prioritizes information researched by various government entities.
Pay attention to the domain in web addresses to evaluate each source. The following domains will most likely publish academic-level information
- .edu (educational institution)
- .gov (government agency)
- .mil (military organization)
Stay critical as ever, and use this domain evaluation as a supplement to CARDS or SIFT.
Tools and Library Resources for Evaluating Information
Fact Checking Sites
- FactCheck.org - Annenberg Public Policy Center’s nonpartisan, nonprofit “consumer advocate” for voters that aims to reduce the level of deception and confusion in U.S. politics.
- Politifact - PolitiFact is a fact-checking website that rates the accuracy of claims by elected officials and others who speak up in American politics. PolitiFact is run by editors and reporters from the Tampa Bay Times, an independent newspaper in Florida.
- SciCheck - Focuses exclusively on false and misleading scientific claims that are made by partisans to influence public policy.
- All Sides - Provides multiple angles on the same story.
Image Checking Sites
- Google Reverse Image Search - Upload or use a URL image to check the content history or to see similar images on the web.
- TinEye Reverse Image Search - Search by image and find where that image appears online.
- FotoForensics - Identify parts of an image that may have been modified or “photoshopped”.
Web History Checking Site
- Wayback Machine - Web archive that captures websites over time and can be used to verify content history and edits.
- Last Updated: Dec 5, 2023 5:18 PM
- URL: https://guides.iona.edu/researchessentials
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