Plagiarism policies may apply to work submitted within virtually any subject or university department. The main subjects associated with potential plagiarism are those within which students submit written content such as essays. Many subjects across the arts, sciences and business involve essay writing that could be plagiarized. Other types of content many also be checked for plagiarism, and so policies may cover more than the obvious subjects.
Essays, dissertations, thesis reports and presentations are works that may be checked for plagiarism. However, there are many other types of content that can contain plagiarized material, such as scientific theories and hypotheses, computing and engineering projects and any content involving critical thinking. There are actually very few university subjects that do not potentially involve plagiarism, so it is always an issue for students and teaching staff.
What counts as plagiarism is matter for debate, and university policies vary. In general, copying or paraphrasing text without a citation will always be considered plagiarism. The work copied may include material that is published in print or digital form (for example on the Internet), and the work of other students. Copying an argument or idea may also be considered plagiarism, although this can be more difficult to identify and prove. In some cases, universities do not permit students to include their own work from previous assignments within submitted work, regarding this as plagiarism.
There has been a rise in online services offering written coursework for students who are willing to pay. These websites and services claim that the work provided is for illustration rather than plagiarism, but universities often consider the submission of such material to be plagiarism. Software solutions have also increased in availability, allowing university staff to scan submitted work to be checked against databases or Internet sources for duplicated text.
There are some exceptions to plagiarism where students have included information that they did not originate within a piece of submitted work. The main example of this is where the information is "commonly known" within the field. Common knowledge within an area of study typically does not need to be attributed, but it can be arguable what content is common knowledge.