Overview of Terms

The Common Types of Plagiarism

“To plagiarize” comes from the Latin word “plagiare” which means, “to kidnap.” There are many ways to “kidnap” or steal ideas, both intentional and unintentional. As a member of an academic community that takes the sharing of ideas and information very seriously, it is important to avoid even the suspicion of plagiarism. To that end, it is your responsibility to learn how to cite your sources. It is also important to remember that understanding your materials is paramount to writing a good paper, and that plagiarizing reveals a lack of confidence in your own understanding. If you are ever tempted to kidnap someone else’s words or ideas – think again – and go to your professor for help.

There are different types and degrees of plagiarism. We've defined the most common types below and have provided links to examples.

Direct Plagiarism

Direct plagiarism is the word-for-word transcription of a section of someone else’s work without attribution. The deliberate plagiarism of someone else's work is unethical, academically dishonest, and grounds for disciplinary actions, including expulsion.


Self-plagiarism occurs when a student submits his or her own previous work, or mixes parts of previous works, without permission from all professors involved. For example, it would be unacceptable to incorporate part of a term paper you wrote in high school into a paper assigned in a college course. Self-plagiarism also applies to submitting the same piece of work for assignments in different classes without previous permission from both professors.

Mosaic Plagiarism

Mosaic Plagiarism occurs when a student borrows phrases from a source without using quotation marks, or finds synonyms for the author’s language while keeping to the same general structure and meaning of the original. Sometimes called “patch writing,” this kind of paraphrasing, whether intentional or not, is academically dishonest and punishable – even if you footnote your source!

Accidental Plagiarism

Accidental plagiarism occurs when a person neglects to cite their sources, or misquotes their sources, or unintentionally paraphrases a source by using similar words, groups of words, and/or sentence structure without attribution. Students should learn how to cite their sources and to take careful and accurate notes when doing research. (See the Note-Taking section on the Academic Honesty page.) Cases of accidental plagiarism are taken seriously and they can be brought before a school’s judiciary board.

This information was derived from a collaborative project originally funded by the Center for Educational Technology, Middlebury College, and developed by the CBB, Colby, Bates, and Bowdoin Colleges. The original pages are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License. Please direct questions and enquiries tomhanraha@bates.edu

Common Knowledge

A statement considered to be "common knowledge" does not need to be attributed to a source. Facts that can be found in numerous places and are likely to be found by many people are likewise considered common knowledge. For example, it is common knowledge that Nathaniel Hawthorne and Franklin Pierce were famous graduates of Bowdoin College. However, it is not common knowledge that President Pierce appointed Hawthorne as the U.S. Consul in Liverpool in appreciation of the author's campaign biography of candidate Pierce in 1852. This latter fact is proposed by Charles Calhoun, A Small College in Maine: Two Hundred Years of Bowdoin (Brunswick: Bowdoin College, 1993), pp. 164-165.

As a general rule well-known or basic facts do not need to be documented; however, interpretations of such facts do.

If something is not common knowledge, or if you are not certain whether it is or not, cite the source. During the course of your studies, you will need to be able to distinguish between different kinds of common knowledge: common knowledge for the general public versus common knowledge for a specialized audience.