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OASIS Writing Skills

Using Evidence:
Citing Sources Properly

This guide includes instructional pages on using secondary sources as evidence in writing.


Citing sources properly is essential to avoiding plagiarism in your writing. Not citing sources properly could imply that the ideas, information, and phrasing you are using are your own, when they actually originated with another author. Plagiarism doesn't just mean copy and pasting another author's words. Review Amber's blog post, "Avoiding Unintentional Plagiarism," for more information! Plagiarism can occur when authors:

  • Do not include enough citations for paraphrased information,
  • Paraphrase a source incorrectly,
  • Do not use quotation marks, or
  • Directly copy and paste phrasing from a source without quotation marks or citations.

Read more about how to avoid these types of plagiarism on the following subpages and review the Plagiarism Detection & Revision Skills video playlist on this page. For more information on avoiding plagiarism, see our Plagiarism Prevention Resource Kit.

Also make sure to consult our resources on citations to learn about the correct formatting for citations.

What to Consider

Citation issues can appear when writers use too much information from a source, rather than including their own ideas and commentary on sources' information. Here are some factors to consider when citing sources:

  1. Did I provide adequate commentary on the cited material?
    Remember that the cited material should illustrate rather than substitute for your point. Make sure your paper is more than a collection of ideas from your sources; it should provide an original interpretation of that material. For help with creating this commentary while also avoiding personal opinion, see our Commentary vs. Opinion resource.
  2. Did I begin and end my paragraphs in my own voice?
    The opening sentence of each paragraph should be your topic sentence, and the final sentence in the paragraph should conclude your point and lead into the next. Without these aspects, you leave your reader without a sense of the paragraph's main purpose. Additionally, the reader may not understand your reasons for including that material.
  3. Have I used the cited material to support my specific thesis?
    All material that you cite should contribute to your main argument (also called a thesis or purpose statement). When reading the literature, keep that argument in mind, noting ideas or research that speaks specifically to the issues in your particular study. See our synthesis demonstration for help learning how to use the literature in this way.
  4. Have I relied too heavily on one source?
    Most research papers should include a variety of sources from the last 3-5 years. You may find one particularly useful study, but try to balance your references to that study with research from other authors. Otherwise, your paper becomes a book report on that one source and lacks richness of theoretical perspective.
  5. Have I included too many direct quotations?
    Direct quotations are best avoided whenever possible. While direct quotations can be useful for illustrating a rhetorical choice of your author, in most other cases paraphrasing the material is more appropriate. Using your own words by paraphrasing will better demonstrate your understanding and will allow you to emphasize the ways in which the ideas contribute to your paper's main argument.

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