Chapter 5: Using information ethically

5.2 How to cite

Once you have done your research and found sources, the next step is writing your paper. As you write, you’ll need to communicate your ideas to your audience. You’ll also need to demonstrate that you know how to integrate others’ ideas in your writing in an ethical, clear, and consistent way. This means incorporating citations when paraphrasing or using direct quotes.

Cite purposefully

Citations aren’t just there to fill up space. Each citation you include in your paper should be relevant and serve a purpose. Maybe you agree with the author and wish to further explore their main points. Or perhaps you disagree with their conclusions and wish to explain your own perspectives. In either case, the ideas you are citing must somehow add to your argument. Keep in mind that no single article or book will be exactly what you need. To strengthen your argument, you need to examine the work of multiple authors.

When to use direct quotes

Sometimes an author presents an idea in a way that you cannot rephrase without losing something important from the original quote. In these cases, you can use a direct quote by copying the text and putting it into your paper with quotation marks around the phrase –and citing, of course!

When you do this, keep the quote as short as you can and still make your point. Be careful not to rely too heavily on quoted material. Remember, the purpose of research is to make an original argument, and not to just pull together big blocks of quotes.

You may have been told at some point that you don’t need to use quotation marks unless you copy some specific number of words in a row from an author’s work. There’s more to it than that. If the author has used words or phrases in a distinctive way, make sure that you use quotation marks if you use the same words in your paper. For example, a source might define a new process or system that must be cited, such as “action painting,” a term which combines common words in a new way, and was coined by a specific art critic.


There are times when an exact quote is the best option for your paper, but most of the time, you’ll be paraphrasing the sources you cite. Paraphrasing refers to incorporating someone else’s ideas into your work and restating them in your own words. This means more than simply swapping out a few words for synonyms. When you paraphrase, you analyze the ideas presented, synthesize that information, and summarize it while citing the original source. By paraphrasing well, you demonstrate that you have understood an author’s ideas, and that you can restate them without altering the author’s meaning.

Tips for paraphrasing

  • Understand your source: when you understand someone else’s perspective and how it fits into your argument, only then can you put those ideas in your own words. Most writing guides will recommend that you read and reflect on the main points that may be relevant to your project.
  • Be true to the source: you must accurately represent the message of the original author in your paraphrasing. This doesn’t mean you have to agree with the ideas, just that you explain them accurately.
  • Acknowledge the source: you must always cite the source whenever you paraphrase. Citing acknowledges that you are using someone else’s ideas whether or not you are using the exact words of the original author. Not citing paraphrased material is plagiarism. Your work is strengthened when you show that you have done your research; citing other writers’ works is your evidence!

It is okay if you don’t feel confident paraphrasing yet. This skill can be challenging and takes practice.

You can get help learning about paraphrasing, citing sources, and structuring your bibliography at the Writing and Communication Consultations.

Common knowledge

Common knowledge is factual information that can easily be verified in multiple authoritative sources (e.g., encyclopedias, dictionaries, reputable websites, and books). You always need to cite things like opinions, ideas, or new research findings, but well-established facts don’t need citations. Even if it’s something new to you, if it’s a long-held fact, it is considered common knowledge and doesn’t need to be cited.

Here are some types of common knowledge, with examples of each:

  • Widely-known facts: that water boils at 100° Celsius.
  • Uncontested historical dates: 1776 was the year the Declaration of Independence was signed in the United States of America.
  • Well-known cultural references, such as important facts, people, or historical events within that culture: Suleiman the Magnificent was the longest ruling sultan of the Ottoman Empire.

These examples were adapted from MIT’s Academic Integrity Handbook for Students.[1]

Be aware that some common knowledge may also be contextual. For example, what is common knowledge among microbiologists may not be common knowledge among lawyers, and vice versa. But if you have any doubt whether something is or isn’t common knowledge, the best practice is to cite.

  1. Massachusetts Institute of Technology. (n.d.). What is common knowledge? Academic integrity at MIT: A handbook for students.


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