What is ‘common knowledge’? 

Generally, common knowledge is information that someone finds undocumented in at least five credible sources. For example, writing is difficult,” is considered common knowledge in the field of composition studies because at least five credible sources can back the claim up.

Remember the golden rule: When in doubt, just cite.

If the citation proves unnecessary or unnecessarily repetitive your instructor or supervisor will inform you.

How does citation work? What is attribution? 

Many professional organizations, including the Modern Language Association (MLA) and the American Psychological Association (APA), have lengthy guidelines for citing sources. We have resources to help you use these guidelines (linked on the sidebar to the left, just underneath this page). But many students are so worried about how to cite a particular source that they never learn how the citation system works. This is often why students end up accidentally plagiarizing. 

Different citation styles have different rules. You should look at the rules for your own (not just the examples that show you how to cite a book chapter). But generally, here is how citation works: 

There are three elements: signal phrase (also called “signposting”), in-text citation (also called “parenthetical citation”), bibliographic citation.  

• A signal phrase is something like “According to Chen Li...” 
• An in-text citation will look like (Li, 2020) or (Li 7) 
• A bibliographic citation will look like: Li, C. (2020). Best practices to avoid plagiarism. Journal of Basic Writing, 42(1), pp. 4-12.  

The signal phrase and the in-text citation show up in the sentences of your paper. The bibliographic citation shows up in the references/works cited/bibliography at the end of your paper, or possibly footnotes at the bottom of each page. You need all three to effectively attribute ideas and words to their proper sources of origin.  

The signal phrase and the in-text citation work together. The signal phrase shows up when you first start talking about a source. It says to the reader “hey! I am drawing on someone else’s idea.” You might use more than one signal phrase if you talk about a source for a few sentences or throughout a paragraph. Then, when you are done talking about that source, the in-text citation ends the sentence. It says to the reader “hey! This is the end of me talking about this source for now. Here is the information you will need to go to the bibliography and find the source I’m talking about.” The bibliographic citation then provides all the information the reader needs to go find the source you looked at. It also tells the reader a number of things before they even do that: the author, how current the source is, its title, and where it was published (like an academic journal, a news site, or a book with lots of chapters). 

Here's an example of what all that looks like put together, using APA:

In this example, I opened with a signal phrase that included the author’s name and the year, to tell my reader who I am citing from. Then I summarized Li’s point in the rest of the first sentence. The second sentence includes paraphrase, where I restated her ideas in my own words, and a direct quote in quotation marks, where I used her words exactly. The in-text citation only includes the page number in this case, because I just gave the rest of the citational material a few words earlier. I could have also written (Li, 2020, pg. 7) and that would have been correct. Then I gave all the information about this (made-up) journal article in my references. 

Look at some articles in a journal in your field — maybe class readings, or sources for your own research project. Pay attention to how the authors attribute sources. Look for signal phrases, in-text citations, and bibliographic citations, and try to see the patterns in how these authors use them. Each field is different — this is just one example.  

See also our resource on quoting, paraphrasing, and summarizing. You can’t cite appropriately if you are not sure exactly how you are using source material.