Plagiarism is the representation of an author's work as unique when, in truth, the work derived from other sources. Typically, plagiarism is thought of as directly copying the text of one writer and passing it off as the work of another. However, according to U.S. copyright laws, plagiarism also includes derivative works. If only a single source of information or preexisting work is used to develop another work, the secondary work is deemed a derivative work, which is in direct violation of copyright laws.
For example, rewriting the Declaration of Independence into modern language would be considered a derivative work if no other source is used. An interpretive sketch of the Mona Lisa would be another example of a derivative work. Such works are considered plagiarism unless the original source is attributed and meets allowable use standards.
At a minimum, best practices for citing sources dictate that writers supply a list of sources in endnotes, a bibliography or a references list. In-text citations further inform readers exactly which portions of a written work include facts or quotes from sources listed in the endnotes or bibliography. For particularly lengthy works, the use of footnotes helps readers easily identify sources used for each page of text. In terms of best practices, the use of in-text citations and a reference list at the end of a written work are expected.
Written works generally conform to one of four writing and formatting styles depending on the intended audience. Such styles dictate best practices for document format specifics, such as use of a title page and line spacing as well as proper source citation formatting. For academic works, the most common styles for citing sources include APA, MLA and Chicago-Turabian styles. These styles outline formatting requirements for all forms of citations, including in-text and reference lists. For professional works, the Associated Press (AP) style is considered the norm for formatting. Each style guide offers tips for citing research from a variety of sources, including personal interviews, written works, online and print publications, and works with more than one author.
Best practices for citing sources -- no matter the specific style used -- require that all sources receive proper attribution and citation. When a fact, quote or derivative statement is used, indicate the original source via a short in-text citation followed by full source specifics at the end of the work. Examples of in-text citations include parenthetical notes at the end of a sentence or are included as part of the sentence structure, such as "according to XYZ Publication." The reader should be able to use the listed information to find the exact source, including page number and other particulars, with little or no effort. In effect, the reader should be able to access the exact source and examine such, just as the writer did during her research.