Is Paraphrasing Plagiarism? Examples of Acceptable and Plagiarized Paraphrases

A paraphrase puts a source's idea into your own wording and tells the reader whose idea it is. Each job can fail on its own.

• Wording too close. The sentence still follows the source's words or structure. Penn Libraries' guide to paraphrase warns that "Even paraphrases with citations can be instances of plagiarism" when they stay that close.
• Credit missing. The wording is new, but the source goes unnamed. The U.S. Office of Research Integrity calls this plagiarism of ideas.

A wording problem needs quotation marks or a real rewrite. A credit problem needs a citation. Fixing one never fixes the other.

Source passage (invented for this guide; the Okafor 2022 citation is fictional): "Commuter students who spread their study time across several short sessions each week remembered considerably more course material than classmates who crammed in one long session before the exam. The benefit was greatest when each session ended with a brief self-test. For students with little time on campus, how study hours are distributed may matter more than how many are logged." (Okafor, 2022, p. 41)

Version 1: copied word for word, with a citation

Commuter students who spread their study time across several short sessions each week remembered considerably more course material than classmates who crammed in one long session before the exam (Okafor, 2022, p. 41).

Verdict: plagiarism of wording. Without quotation marks, the source's words pass as the writer's own. The Office of Research Integrity's examples of good and bad paraphrasing reject even a credited near-copy, because "most of the words and structure of the original paragraph are preserved." Fix: add quotation marks, or close the source and write it again.

Version 2: synonyms swapped, same structure, with a citation

Students who commute and divide their study time over a number of brief sessions every week recalled far more class material than peers who packed everything into a single lengthy session ahead of the test (Okafor, 2022).

Verdict: patchwriting. Every clause sits where Okafor put it, with "brief" for "short" and "lengthy" for "long." Yale's Poorvu Center judges a cited example built the same way: "This kind of cosmetic changing that leaves the original intact is unacceptable." Fix: close the source and rebuild the sentence from its point. Starting with the conclusion helps.

Version 3: source phrases woven into new sentences

Cramming may be a poor strategy for commuters. Okafor (2022) found that students who spread their study time across several short sessions each week did better, which suggests that how study hours are distributed may matter more than how many are logged.

Verdict: mosaic plagiarism. Two long phrases are Okafor's, word for word and unmarked. The citation credits the idea, not those words. Fix: quote a phrase only if its exact wording matters, and rewrite the rest.

Version 4: new words, no citation

For students who commute, when they study may count for more than how long. Several short sessions across the week beat one long cram before the exam, and the gain grows when each session ends with a quick quiz.

Verdict: plagiarism of ideas. The sentences are the writer's own. The finding is Okafor's, and nothing says so. Fix: name the source, for example "According to Okafor (2022), ...".

Version 5: new words, with a citation

According to Okafor (2022), commuters who broke their studying into smaller blocks across the week retained more than those who studied in one sitting before an exam, especially when each block closed with a quick quiz. When campus time is scarce, Okafor suggests, the timing of study may count for more than its total (p. 41).

Verdict: acceptable. Structure and vocabulary are new, and the source is named. The hedge survives too. Okafor says the distribution of study time "may" matter more, and the paraphrase keeps that "may."

The Poorvu Center calls the pattern in version 3 mosaic or patchwork plagiarism. In its guide to fair paraphrase, the writer of one example "has taken phrases verbatim from the original, rearranged them somewhat, and woven them into the fabric of her own writing." Her example ends with a page citation and is still plagiarism. The same guide adds that a page number "doesn't absolve you of the need to represent the idea in your own words."

Patchwriting is Rebecca Moore Howard's term. Her 1995 College English article includes a sample plagiarism policy, which Purdue's Online Writing Lab reprints. The policy defines it as "Writing passages that are not copied exactly but that have nevertheless been borrowed from another source, with some changes." It counts patchwriting as plagiarism "regardless of whether one supplies footnotes, endnotes, or parenthetical notes that acknowledge the source." That is version 2.

The same policy calls patchwriting "a transitional writing form" that is "never acceptable for final-draft academic writing." When it comes from inexperience with academic conventions or unfamiliarity with the source, the policy points to instruction and a request for revision. When it comes from an "intent to deceive," the minimum penalty is an F in the course.

1. Read the passage until you can explain its point without looking.
2. Put the source away and write your version from memory.
3. Compare the two. Quote or rewrite any phrase that survived word for word.
4. Check that the claim did not change. A "may" in the source stays a "may" in yours.
5. Cite the source. Our guide to citing a paraphrase covers the format.

Our guide to what paraphrasing is covers the full technique. To turn a quotation you collected into your own sentence, see how to paraphrase a quote.

The Poorvu Center applies the same test to AI: "Asking generative AI tools to paraphrase a source and using the output without acknowledging the source is plagiarism." Your course may also require you to disclose AI use. If you rework your own draft with the Certentis Humanizer, it is built to keep citations, quotations and claims intact. Check the result against your draft and the source anyway. Every quotation still needs its marks, and every borrowed idea still needs its citation.

A similarity check compares your wording with the sources it can reach and highlights what matches. If Okafor's text were among them, the five versions would likely look like this.

Versions 4 and 5 can produce the same near-empty report, yet only one is acceptable. The difference is whether the idea is credited, and matching text cannot show that. A low match does not prove a paraphrase acceptable.

In a 2007 study of text-matching reports, Keuskamp and Sliuzas analyzed the reports of 21 students at one Australian university. The software flagged inadequate paraphrases as well as verbatim copying. Yet the match percentages alone were not enough to judge whether plagiarism had occurred. The authors call for careful interpretation of each report.

The Certentis plagiarism checker marks exact matches and similar wording separately and shows the sources behind each highlighted passage. That helps you find and fix passages like versions 1 to 3 before you submit. It cannot judge whether a paraphrase is fair or whether every idea is cited, and it only finds sources it searched. Our guide to reading a similarity report explains the highlights.