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English 120 Communication Skills: Writing

A guide to library resources and research for ENG110, 120, and 122 students

Evaluating Your Sources

Primary sources 

  • According to the Library of Congress "primary sources are the raw materials of history - original documents and objects which were created at the time under study." They are the "actual records that have survived from the past, such as letters, photographs, articles of clothing."


Secondary Sources

  • According to Princeton University, "a secondary source interprets and analyzes primary sources. These sources are one or more steps removed from the event." They encompass and either interpret or explain primary data and artifacts.
    Note: Peer-reviewed publications generally fall into this category.


Tertiary Sources

  • According to BMCC, "Tertiary sources consist of information which is a distillation and collection of primary and secondary sources."  Items such as synopses, indexes, bibliographies and almanacs generally fall into this category.

For more in-depth information about primary and secondary sources, see the Evaluating Sources page of the Research Essentials research guide.

Regardless of the type of resource you are examining, always evaluate the accuracy and reliability of the information you find before using it for your research. Use the acronym CARDS to help you do that evaluating. Consider the following when determining the quality of an article or source:

Use C.A.R.D.S.


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, is the author reputable? 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, but can actually produce inaccuracies in information.

  • Do they cite the sources of their information? 

R - Reliability:

  • Is the source objective or does it advocate a certain point of view?  Use objective sources first, but consider using those advocating different points of view as well.

  • Is the information free of advertising or clearly separated from it?

D - Date:

  • Can you find the copyright date?

  • Are there dates for when it was written or when it was last revised?

  • Do any statistics, graphs, or charts clearly state when the data was collected?

  • Are there links which no longer work?

S - Source:

  • Is the information based on primary or secondary sources? 

  • Are there links to other sources that would score high in this C.A.R.D.S. evaluation?

You can always consult with a librarian at the Research Desk or via email using the Contact A Librarian form.


If you do nothing else, check the author. The first step to credibility is a name brand. If there is no author, or your author doesn't come up as the author of anything else, the article is probably not credible. If you can't trust the writer, you can't trust what s/he wrote.


Use the form of scholarly articles to your advantage when you are doing scholarly research. Scan the bibliography of relevant articles to find more research materials. Don't use all of one author's sources in your paper, but use the bibliographies of scholarly articles to find more articles.

Found an article you think is scholarly but it doesn't have a bibliography? Leave that article and find a new one. Bibliographies are crucial to the peer review process, and the article is likely not scholarly without a bibliography. A source without a bibliography is also a research dead-end; you can't use it as a spring board to other articles.

By understanding domain names, you get a better sense of where each article is hosted on the internet. The most common domain names are:

  • .com (commercial or business)

  • .edu (educational institution)

  • .gov (United States government agency)

  • .mil (United States military organization)

  • .net (network resource)

  • .org (organization)

.org accounts used to be more difficult to obtain in the early 2000's, often requiring organizations to submit papers proving that they were a functioning and financially transparent non-profit organization. That is no longer the case. Just because a group claims to be a reputable organization with a .org domain, be curious about that organization and do a bit of background research.

You can search for web pages from a particular domain, such as in the search "climate change" site:gov or clean water site:org

For more information about evaluating internet resources, see the Evaluating Sources page of the Research Essentials research guide.