Plagiarism, Authorship & Citation
Credit is the currency of research: who did the work, whose ideas these are, where the evidence came from. Most integrity failures here aren't dramatic. They're a paragraph reused without a nod, a name added as a favor, a statistic cited from a paper you never actually read. Each feels minor, and each misrepresents the record. This lesson covers the three places credit goes wrong: the words (plagiarism), the byline (authorship), and the sources (citation). Then it hands you six real-feeling dilemmas to work through.
Plagiarism is more than copy-paste
Plagiarism is presenting someone's words, ideas, or work as your own. It comes in more forms than students expect:
- Verbatim. Copying text word-for-word without quotation marks and a citation — the obvious case.
- Mosaic / patchwriting. Swapping in synonyms and shuffling a source's sentence while keeping its structure. Adding a citation doesn't rescue it: if the wording is basically theirs, quote it; if you're paraphrasing, rebuild the idea in your own structure.
- Self-plagiarism. Reusing your own previously submitted or published work as if it were new: recycling last year's essay into your thesis, or republishing the same results. Your own words still need disclosure and, where the earlier work was assessed or published, a citation.
- Idea theft. Taking someone's argument, design, or unpublished finding and presenting it as your own, even if not a single sentence is copied.
Paraphrase, done right: read the source, look away, restate the point in your own words and sentence shape, and cite it. Cite for the idea, quote for the wording. Both need attribution: a citation covers the idea, quotation marks cover the exact words.
Who counts as an author
Authorship means credit and accountability, so it can't be handed out as a gift or a thank-you. The widely used ICMJE standard asks for all four of these, not just one:
- Substantial contribution to the conception, design, data, or analysis;
- Drafting the work or revising it critically for important content;
- Final approval of the version to be published;
- Accountability for the work, agreeing to be answerable for its integrity. This last one is why an AI tool cannot be an author however much of the drafting it did: software cannot answer for anything.
Two failures follow directly. Gift (or honorary) authorship lists someone who didn't meet the criteria: a lab head, a friend, a favor for a CV. Ghost authorship omits someone who did — the student who ran the study, or an industry writer kept off the byline. Both distort who is responsible. People who helped but don't meet all four criteria belong in the acknowledgements, not the author list; and author order should reflect contribution, agreed openly and early (with a contributions statement, or co-first authorship when the work truly was equal).
Citation ethics
Citations are promises about where knowledge came from, so two rules matter. Cite what you actually read. If you found a 1998 statistic quoted in a 2020 review but never read the 1998 paper, don't cite the original as though you did; read it, or write "(1998, as cited in 2020 review)". Citing sources you've only seen second-hand launders unverified claims into your work and passes on any errors. And cite generously and accurately: attribute ideas to whoever had them, don't inflate your reference list with papers you didn't use, and don't strip a citation to make an idea look original. The mechanical half of this is a checkable task rather than a judgment call, and it belongs on the final pass: every citation in the text present in the reference list, and every entry in the list actually cited.
Work the dilemmas
Six situations you could plausibly face. For each, pick the response you think fits the guidelines, then compare with the guideline-based answer and its reasoning. They're judgment calls; what matters is the reasoning, not a perfect score.
⚖️ Authorship & citation dilemmas
Pick a response, then reveal the guideline-based answer.
Credit tracks contribution, not politics. The honest test for a byline is the work someone actually did, not their seniority, their feelings, or a favor owed — and the honest test for a citation is whether you truly used the source. Get both right and you're not just avoiding misconduct; you're keeping the record trustworthy for everyone who reads it next.
Why it matters: plagiarism and authorship disputes are among the most common and most career-damaging integrity cases students hit, and almost all of them are avoidable with habits set early: paraphrase properly and quote when in doubt, agree authorship and order at the start of a project in writing, and only ever cite what you've read. When a case is genuinely unclear, ask your supervisor or your institution's research-integrity office before you act, not after.
Common questions
Can I reuse text from my own earlier assignment?
Not by silently pasting it in; that is self-plagiarism. Reusing your own previously submitted or published work as though it were new misrepresents it, and most institutions treat re-submitting an assessed essay as an academic-integrity issue. If the earlier work was graded or published you should cite it, and you should rework the material for its new context rather than dropping identical paragraphs into a thesis; swapping a few words to disguise the reuse (patchwriting) does not help. Building on your own earlier writing is normal and fine — the honest way to do it is to disclose it, cite it, and rewrite. If you are unsure of your program's specific rules, ask your supervisor before you reuse anything.
Does my supervisor automatically get authorship?
No. Authorship is earned by contribution, not by job title. Under the widely used ICMJE criteria an author must make a substantial contribution to the work, help draft or critically revise it, approve the final version, and agree to be accountable for it. A supervisor who shaped the design, guided the analysis, and revised the manuscript clearly qualifies, and in practice many do. But merely heading the lab, providing funding, or giving occasional feedback is not enough on its own; listing someone on that basis is gift (honorary) authorship. The opposite error (dropping a student who did qualifying work) is ghost authorship. The fix for both is to agree authorship and order openly and early, based on who actually does what.
How much do I have to change a sentence for it to count as a paraphrase?
There is no word count that makes it safe, and looking for one is the mistake. Swapping in synonyms while keeping the source's sentence shape is patchwriting, and it stays patchwriting whether you changed three words or thirty, because the structure that carried the idea is still theirs. The test that actually works is procedural: read the passage, put it out of sight, and write the point from memory in the shape your own paragraph needs. If you cannot do that, you have not finished understanding it yet, which is useful information. Then cite the source anyway, because paraphrasing removes the need for quotation marks and never the need for attribution. When the original wording is genuinely worth keeping, quote it and move on.