Plagiarism and common knowledge
As has been pointed earlier, one must give credit to those whose ideas and facts we are using. One general exception to this principle occurs when the ideas we are discussing represent ‘common knowledge’. If the material we are discussing is assumed to be known by the readership, then one need not cite its origin. Suppose you are a student writing a paper on the history of the United States for a college course and in your paper, you mention the fact that George Washington was the first president of the United States. Must you provide a citation for that pair of facts? Most likely not, as these are facts commonly known by average American college and high school students. The general expectation is that “everybody knows that”. However, suppose that in the same paper the student must identify the 23rd president and his running mate and the main platform under which they were running for office, plus the year they both assumed power. Should that be considered common knowledge? The answer is probably no. It is doubtful that the average American, would know those facts. In fact, I had to look up the answers.
Let’s take another example. Imagine that we are writing a paper and in it we have a need to discuss the movement of sodium and potassium ions across a cell’s membrane (see the Martini and Bartholomew paragraph above). Surely, those ideas are not common knowledge amongst college students and if they were expected to use those concepts in a paper they would be required to provide a citation. However, let’s suppose that the individual writing the paper was a seasoned neuroscientist and that she intended to submit her paper for publication to a professional journal. Would the author need to provide a citation for that material? Not necessarily. Although for the non-scientist the description of the concentration gradients of sodium and potassium ions inside neurons may look sufficiently complex and unfamiliar, the material is considered common knowledge amongst neuroscientists. It would, indeed, be shocking to find a neuroscientist or biologist who was not familiar with those concepts.
Therefore, the question of whether the information we write about constitutes common knowledge depends on several factors, such as who the author is, who the readers are, and the expectations of each of these groups. Given these considerations, we recommend that authors abide by the following guideline:
Guideline 9: When in doubt as to whether a concept or fact is common knowledge, provide a citation.
About this Material
Avoiding plagiarism, self-plagiarism, and other questionable writing practices: A guide to ethical writing
The purpose of this module is to help students, as well as professionals, identify and prevent questionable practices and to develop an awareness of ethical writing. This guide was written by Miguel Roig, PhD, from St. Johns University with funding from Office of Research Integrity.