There are some actions that can almost unquestionably be labeled plagiarism. Some of these include: buying, stealing, or borrowing a paper (including, of course, copying an entire paper or article from the Web); hiring someone to write your paper for you; and copying large sections of text from a source without quotation marks or proper citation.
But then there are actions that are usually in more of a gray area. Some of these include using the words of a source too closely when paraphrasing (where quotation marks should have been used) or building on someone's ideas without citing their spoken or written work. Sometimes teachers suspecting students of plagiarism will consider the students' intent, and whether it appeared the student was deliberately trying to make ideas of others appear to be his or her own.
However, other teachers and administrators may not distinguish between deliberate and accidental plagiarism, so let's look at some strategies for avoiding even suspicion of plagiarism in the first place
The key to avoiding plagiarism is to make sure you give credit where it is due. This may be credit for something somebody said, wrote, emailed, drew, or implied. Many professional organizations, including the Modern Language Association (MLA) and the American Psychological Association (APA), have lengthy guidelines for citing sources. However, students are often so busy trying to learn the rules of MLA format and style or APA format and style that they sometimes forget exactly what needs to be credited. Here, then, is a brief list of what needs to be credited or documented:
Bottom line, document any words, ideas, or other productions that originate somewhere outside of you.
There are, of course, certain things that do not need documentation or credit, including:
Generally speaking, you can regard something as common knowledge if you find the same information undocumented in at least five credible sources. Additionally, it might be common knowledge if you think the information you're presenting is something your readers will already know, or something that a person could easily find in general reference sources. But when in doubt, cite; if the citation turns out to be unnecessary, your teacher or editor will tell you.
Text used with permission from The Writing Lab & OWL at Purdue University https://owl.english.purdue.edu/owl/resource/589/02/