This is a reposting of a blog post from the APA Style Blog that was published in May 2016.
Principles of Good Writing: Avoiding Plagiarism
by Harris Cooper, PhD
Committing plagiarism can have devastating effects on your education or career. Perhaps most distressing is that it is so easily avoided.
Plagiarism involves the copying of text into a new work without crediting it to the original source. The main reasons why people plagiarize are simple. First, they want credit for someone else’s ideas. This motivation can come from a desire to impress others and to foster career advancement. Second, it can occur because people are just plain lazy. They have found a passage written by another that fits their paper well and is expressed clearly. They think it would be too much effort to rephrase and credit the source.
Instances of plagiarism can range from stealing an entire work, by simply changing the name of the author, to paraphrasing someone’s work and not attributing the ideas to the original written document (Turnitin, 2012). Also, motivation can be used to distinguish among acts of plagiarism (Barnett & Campbell, 2012). Plagiarism can be intentional or conscious. It can also be unintentional or inadvertent; for example, when you read something and then later forget that it had a source other than yourself. Regardless of the motivation, plagiarism is plagiarism, and the possibility of unintentional plagiarism means the steps you take to avoid it ought not be based on your memory alone.
Students often ask “how many words in a row constitute plagiarism?” There is no black-and-white answer to this question. Different people will answer differently. Also, context might matter. For example, it is not unusual to find descriptions of research apparatus and psychological measures that share short strings of words without attribution to the original source, and without engendering charges of plagiarism.