Skip to Main Content

Citations & Plagiarism: APA, MLA, and more

Use this guide to learn how to format your work in APA, MLA, and Chicago style, and to avoid plagiarism.

Recognizing plagiarism

What is plagiarism?

Plagiarism can be unintentional or intentional when you use someone else's ideas or work without citing it. Common forms of plagiarism can include:

  • Passing off another’s ideas or work as your own
  • Making up citations
  • Copying and pasting information without citing the original source
  • Paraphrasing incorrectly
  • Using image and media files without citing them

You don't need to cite general common knowledge—facts or statements like "George Washington was the first American president" are widely known and can be found in many sources, so a citation is not needed. Be careful with field-specific common knowledge, though: facts, theories, or methods that are familiar to readers within that discipline may not need to be cited—but be certain they are so widely known that anyone in the field would know it. You can use your common sense for this, but when in doubt, ask!

How do you recognize plagiarism?

It can be hard to identify the kind of grey area plagiarism that can happen intentionally or unintentionally. Many universities have extensive resource guides on plagiarism.  Indiana University has a how-to guide to help you figure out how you are doing, or you can look through Purdue's resources. Both guides give you the chance to check your instincts and think carefully about plagiarism with a short test or practice exercise.

How do you prevent plagiarism?

Consider using tools to help you organize your research and keep your information in one place. Try keeping track of what you're quoting or paraphrasing in a document, dedicated “research journal," or a note-taking app: 

  • Best Note-taking Apps — this PC Mag article links to several reviews of free note taking apps, including web-based tools and mobile apps

You should also practice citing your sources for direct quotes, paraphrases, and images as you write your rough draft. It's much easier to avoid accidental plagiarism if you start out with good practices.

Quoting and paraphrasing

When you are writing a paper or creating a presentation, you read a lot about your topic in order to learn about different aspects or perspectives that can help you fully understand it. After you've done a lot of research, you should be able to form some ideas of your own, and think and talk about the topic in your own words. In order to get there, though, you probably took notes, copied sections of articles, bookmarked links, and saved information on the topic. The materials and sources you used are what you should list in your bibliography and cite in your paper.

Quoting Sources

When you take what someone else has written, and write it word for word, you are quoting the author. Sometimes a phrase or sentence exactly captures the point you are trying to make, or maybe you like the way it is written so much that you want to use it directly. You may also want to give examples of several points of view, or even distance yourself from a source to  make it clear that it is not your point of view. It's okay—you just have to put the words you are copying in quotation marks and cite where you found it.

Paraphrasing Sources

Paraphrasing is when you use the content of an article or paragraph or sentence in your own paper—you take an idea or claim or argument from a source and restate it in your own words. It's fine to paraphrase an idea as long as you reference where you found it. You can even combine ideas from multiple sources into a sentence or section of your paper as long as you acknowledge the sources. Even when you use your own words, if the information or idea comes from a source, you must cite the source. 

Follow these four steps for successful paraphrasing:

  1. Read the entire text, underlining key points and main ideas.

  2. In your own words, write a sentence about the main idea of the text (i.e. summarize). Also, write key points in the text.

  3. Highlight any words, phrases, or key passages that you would want to quote directly.

  4. Combine the above into a new paraphrased paragraph, using your own words.

Be careful not to follow the source too closely when paraphrasing. You want to document your source's material, but also add new material to fit the new context and purpose that you are creating when you write.

Plagiarism resources

Indiana University Bloomington Writing Services

This resource offers many fantastic writing guides to help you with your research assignments, including:

University of Wisconsin-Madison Writing Center

The writing center's online handbook has information and tips on plagiarism, citing, quoting, paraphrasing, and they offer useful, downloadable handouts. This is also a great resource for writing for any audience in any format.

"Just Because You Put it in Your Own Words"


The video below was created by Leonard Lief Library faculty at Lehman College to explain the concept of citing sources in a humorous way.


Should I cite this?

The Purdue OWL "Should I Cite This" poster, developed by Rachel Atherton

Synthesizing information

Research is a process. Once you've identified a research question, searched for answers and sources to help you learn more about your topic, you need to evaluate what you found. Did your sources provide the right information to answer the question? Is the information credible? Do the different sources answer your question in different ways? Try to synthesize what you've learned by connecting the information from all of your sources in your research.