Examples
Worked examples
- Is an instance
A figure shows mouse-organ histology for three treatment groups but two of the panels are the same image rotated 180 degrees.
Counter-examples
Looks similar, but isn't
- Not an instance
A schematic illustration reused across several papers from the same group with consistent attribution and stated reuse.
Editorial commentary
Image duplication is the reuse of an image, or a portion of one, to represent a different experimental condition, time point, or sample than the one it actually came from — most often in Western blots, gel images, and microscopy figures. Bik, Casadevall and Fang’s 2016 audit of biomedical papers found inappropriate image duplication in roughly 4 percent of articles screened, a figure widely cited as the baseline scale of the problem across the field.
Three categories are commonly distinguished, in ascending order of how deliberate they typically look: simple duplication (the identical image appears in two places in a figure or across figures with no acknowledged relationship); duplication with repositioning (the same image rotated, translated, or reflected); and duplication with alteration (the reused image is cropped, resized, or has its contrast or brightness adjusted). A figure legend that implies two panels come from distinct sources, when in fact they are the same underlying image, is what makes duplication problematic — the duplication itself is the finding, not automatically the researcher’s motive.
This is precisely where the honest-error exclusion in the federal misconduct definition matters most: not every duplicated image is misconduct. Figure-assembly errors happen — pulling the wrong file from a shared folder, mislabeling a saved crop — and journals and integrity offices distinguish an isolated, promptly-corrected duplication from a pattern spanning multiple figures or papers, which is treated as evidence of intent rather than a single slip. This is the same distinction that separates duplication from image manipulation: manipulation implies an active, purposeful change to what an image shows, where duplication is frequently — though not always — a sourcing or file-handling error rather than intentional alteration.
Automated screening (ImageTwin and comparable forensic tools) has pushed detection earlier into the publication pipeline, with a growing number of journals now screening figures at submission rather than relying on post-publication scrutiny alone. See EMBO Press’s image-integrity guidelines for a widely referenced editorial standard, and falsification for where a duplication crosses into a federal-misconduct finding.
References
- Bik, Casadevall & Fang (2016) ‘The prevalence of inappropriate image duplication in biomedical research’, mBio 7(3)
- EMBO Press image integrity guidelines (current edition)
Also known as
figure duplication · image reuse
Machine-readable encodings
Use in your systems
<role vocab="credit"
vocab-identifier="https://casrai.org/dictionary/"
vocab-term="Image duplication"
vocab-term-identifier="https://casrai.org/dictionary/term/image-duplication" />{
"@context": "https://schema.org",
"@type": "DefinedTerm",
"@id": "https://casrai.org/dictionary/term/image-duplication",
"name": "Image duplication",
"identifier": "https://casrai.org/dictionary/term/image-duplication",
"description": "The undisclosed reuse of an image, or portion of an image, to represent a different experimental condition, time point, or sample. Duplication is problematic when the figure legend implies the images are distinct sources.",
"inDefinedTermSet": "https://casrai.org/dictionary/domain/research-integrity#set",
"url": "https://casrai.org/dictionary/term/image-duplication",
"sameAs": [
"figure duplication",
"image reuse"
],
"license": "https://creativecommons.org/licenses/by/4.0/",
"publisher": {
"@id": "https://casrai.org/#organization"
},
"author": {
"@id": "https://casrai.org/#editorial-team"
},
"datePublished": "2026-05-21T02:22:52",
"dateModified": "2026-08-22T19:39:41",
"inLanguage": "en-GB",
"isAccessibleForFree": true
}
