If the publishing industry adopted a biblical warning for writers, Leviticus 19:11 would be particularly appropriate: “You shall not steal, nor deal falsely, nor lie to one another.” The verse obviously was not written with websites, digital publishing, research databases, or twenty-first-century authors in mind, but its underlying principle translates surprisingly well.

Writers have more information available to them than at any other time in publishing history. That access can make research faster and richer, but it also makes it remarkably easy to copy, paste, paraphrase, save, and reuse another person’s work without maintaining a clear record of where the material originated.

What Is Plagiarism?

At its simplest, plagiarism occurs when someone presents another person’s words, ideas, processes, or other intellectual contributions without giving appropriate credit. The problem is not limited to copying an entire paragraph or chapter; writers can also plagiarize ideas or closely reproduce someone else’s expression while making only superficial changes. (Office of Research Integrity)

That distinction matters for authors because research often becomes woven into a manuscript gradually. A quotation copied into notes in January may look surprisingly familiar when the writer encounters it again in June, especially if the source information was not recorded alongside it.

Plagiarism and Copyright Infringement Are Not the Same Thing

Writers sometimes use plagiarism and copyright infringement interchangeably, but they describe different problems. Plagiarism is fundamentally about attribution and representing someone else’s contribution as your own, while copyright law governs legal rights in protected expression.

The difference becomes clearer when we consider ideas. Copyright generally does not protect ideas themselves, although it may protect the particular way an author expresses those ideas; plagiarism, however, can involve taking another person’s distinctive idea without acknowledgment and presenting it as one’s own. (U.S. Copyright Office)

The reverse can also happen. A writer could clearly identify and credit the author of a protected passage yet still use more copyrighted material than the law permits without permission, which means attribution alone does not automatically resolve a copyright question.

That is why writers need to think about both issues. The ethical question is whether you have properly acknowledged what came from someone else, while the copyright question is whether you have the legal right to use the protected material in the manner you intend.

Quoting a Source

When you reproduce another writer’s exact words, quotation marks or appropriate block-quotation formatting should make clear which language belongs to the source. The writer should also identify the source according to whatever citation or attribution system is appropriate for the book.

Quoting someone accurately does not mean dropping a passage into a manuscript and adding the author’s name somewhere nearby. Readers should be able to distinguish clearly between your language and the quoted language and, when appropriate, determine where the original material came from.

Paraphrasing Is More Than Changing a Few Words

One common form of accidental plagiarism occurs when a writer believes a passage has been paraphrased because several words have been replaced with synonyms or the sentence structure has been rearranged. A legitimate paraphrase expresses the source material genuinely in the writer’s own language and still credits the original source. (Purdue OWL)

This is especially important when writers work directly beside an open source document. The original phrasing can quietly seep into the new version, producing what is sometimes called patchwriting: language that appears different at first glance but still follows the source too closely.

A better approach is to read the source until you understand the idea, move away from the original wording, explain the concept independently, and then compare your version with the source. You should still cite the source because changing the wording does not transform someone else’s research or idea into your own.

There Is No Universal “300-Word Rule”

The original version of this article advised writers to restrict quotations to 300 words unless they obtained permission. We should remove that statement because U.S. copyright law contains no universal rule allowing 300 words, 200 words, 10 percent, or any other predetermined amount of copyrighted material to be copied automatically.

Fair use is evaluated case by case. Under Section 107 of the Copyright Act, courts consider the purpose and character of the use, the nature of the copyrighted work, the amount and significance of what was used, and the effect of the use on the market for the original work. (U.S. Copyright Office)

Even a relatively small excerpt can raise problems when it takes the most important or distinctive portion of a work. Conversely, some circumstances can support fair use of a larger portion, which is why a simple word-count formula cannot answer the question. (U.S. Copyright Office)

Authors who are uncertain whether a particular use requires permission should therefore avoid relying on publishing folklore about “safe” quotation lengths. For substantial or commercially significant uses, obtaining permission or seeking appropriate legal guidance may be far wiser than guessing.

Keep Your Research Trail Clean

Preventing plagiarism becomes considerably easier when writers treat source management as part of the writing process rather than something to reconstruct immediately before publication. A manuscript containing extensive research deserves a research trail almost as carefully maintained as the manuscript itself.

Simple habits can prevent many problems:

• Record the author, title, publication, URL, page number, and other source details when you first save information rather than planning to find them again later.
• Place quotation marks around exact copied language in your notes immediately, even if you are not yet sure whether the quotation will appear in the manuscript.
• Distinguish your own observations from paraphrases, summaries, and direct quotations while taking notes.
• Cite the source of an idea even when you express that idea completely in your own words.
• Review questionable passages before publication rather than assuming an editor will discover every attribution problem for you.
• When using photographs, illustrations, charts, lengthy quotations, or other third-party material, determine whether permission or another legal basis for use is required.

Those habits matter because memory becomes unreliable over the life of a book project. Months or years can pass between initial research and final publication, leaving writers genuinely unable to remember which observations originated with them and which came from a source.

Editors Can Spot Changes in Voice

The original article makes a point that remains useful: experienced editors often notice when a manuscript suddenly changes voice, vocabulary, sentence rhythm, or level of expertise. A passage written in dramatically different language can prompt an editor to investigate where it came from.

That does not mean every stylistic variation indicates plagiarism, nor should writers assume editors function as human plagiarism detectors. It does mean that copied material can disrupt the integrity of a manuscript in ways the writer may not recognize.

More importantly, finding unattributed material creates a larger question about the rest of the manuscript. If one passage cannot be trusted, an editor or publisher may reasonably need to determine whether other passages have the same problem.

Accidental Plagiarism Is Still Worth Preventing

Not every attribution mistake is deliberate. Writers can lose track of sources, misunderstand citation practices, paraphrase too closely, or attribute information to the wrong source, particularly when working with large amounts of research. (Purdue OWL)

Intent matters when judging someone’s conduct, but it does not make sloppy research practices harmless. The best protection is to create a process in which the origin of borrowed words and ideas remains visible throughout drafting, revising, editing, and publication.

Originality Does Not Mean Writing in a Vacuum

Writers build on knowledge that already exists. Historians rely on records, nonfiction authors consult experts, novelists research places and professions, and scholars enter conversations that began long before their own work.

The goal is not to pretend those influences do not exist. The goal is to distinguish clearly between what you discovered from others and what you are contributing yourself.

Attribution does not weaken an author’s authority. Done properly, it shows readers that the writer has researched the subject responsibly, understands the difference between evidence and personal interpretation, and respects the intellectual work that made the new work possible.

That principle is ultimately larger than avoiding an embarrassing citation problem or an editor’s raised eyebrow. Writers ask readers to trust them, and responsible use of sources is one of the ways that trust is earned.

 

NOTE: Originally published March 2, 2016, by Cormac Lambe. Updated July 2026 to reflect current guidance on plagiarism, attribution, copyright and fair use.