When To Cite
Some of the basic types of sources that require citation are listed and described below as a guide. This is not an exclusive list.
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.
Paraphrasing and Quoting
Paraphrasing enables students to present other people’s ideas in their words. Rewriting another work requires citation. Like direct quotes, paraphrasing must be traced to its original source. A direct quote from an external source duplicates the words of an author or speaker. These words are enclosed within quotation marks. When necessary, direct quotes must be cited correctly and distinguished from your own words. Your work should represent your thoughts and organization, and should strive to strike a balance between the use of direct quotes, paraphrasing, and your own words. A useful guides in this process can be found at http://web.mit.edu/academicintegrity/writing/paraphrasing.html.
Any Information drawn from the internet or electronic sources should be completely referenced, as one would any source that is not yours. This includes direct quotes, paraphrasing or a description of concepts that are not yours. A complete web site address is required such that the author and the location is clearly apparent. As with any source, it is important to verify the authenticity of the web site you are referencing, and this is commonly achieved by evaluating several independent sources.
Also see https://integrity.mit.edu/handbook/citing-your-sources/citing-electronic-sources
Writing Computer Code
The unauthorized copying of computer code can be considered plagiarism. View examples of acceptable and unacceptable code at: https://integrity.mit.edu/handbook/writing-code