Thresholds
| Overall similarity (excluding references and quotations) | Action |
|---|---|
| Below 15%, with no single source above 5% | Proceeds to review |
| 15% – 25% | Returned to the authors to rewrite and cite properly |
| Above 25%, or substantial copying from one source | Rejected; serious cases handled under COPE guidance |
Numbers alone do not decide: the editor reviews the similarity report to judge whether overlap is legitimate (e.g. standard methods descriptions) or not.
What counts as plagiarism
- Copying text, figures or data without attribution
- Paraphrasing someone else's work without credit
- Reusing your own published text or data without disclosure (text recycling)
- Submitting the same work to more than one journal, or publishing it twice
- Presenting AI-generated text as original analysis without disclosure
Consequences
Depending on severity: rejection, correction or retraction of a published article, notification of the authors' institution, and a ban on future submissions.