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Ithenticate at Caltech: Publishers' Use of iThenticate

How Publishers and Funders Use iThenticate in the Submission and Review Process

  • Outside organizations access iThenticate as part of their membership in the DOI Registration agency, CrossRef.  This service is branded as "CrossCheck" or "Similarity Check"
  • Members receive CrossRef alerts for similarity indexes greater than 50%
  • Publishers and agencies may apply their own similarity index thresholds to reject submissions but most rely on their editors to judge the meaning of iThenticate reports . There is, however, some evidence of autorejection thresholds between 20-40%

Do Publishers Check Submitted Manuscripts for Originality Using iThenticate?

Many journal publishers do analyze submitted manuscripts using the iThenticate service, including the American Physical Society (APS), IEEE, Springer-Nature, Elsevier, Public Library of Science (PLoS), and many others. The version of iThenticate that the publishers use is commonly called "CrossCheck", and is part of the publisher services that the DOI Registration Agency CrossRef offers as a value added benefit. When publishers register a DOI for a given article, they submit it for iThenticate similarity checking and also agree to add the published article to the iThenticate database. In this way, the iThenticate database of content being checked for similarity is continuously updated with new papers, proceedings, and books/book chapters.

if you wish to know whether a particular publication is included in the iThenticate database, visit the online page at and type in the title of interest in the the ‘search scholarly journals’ box in the middle of the page (example shown below). If the database includes the journal, the results will display the name of the journal, the publisher, and the number of articles that iThenticate includes.

According to a study commissioned by the international Committee on Publication Ethics (COPE), over 40% of journal editors worldwide screen manuscript submissions against the iThenticate database. They do this via the CrossCheck service - the publisher-facing version of iThenticate available from the DOI agency CrossRef.

An example of a publisher's policies using CrossCheck/iThenticate is available in the Springer Nature CrossCheck Guide online at

In another example, Elsevier has integrated CrossCheck and iThenticate into their editorial submission system to ensure that all manuscripts are checked. Yet Elsevier editors understand the importance of combining the generated similarity reports with sound judgment. As explained by one of their editors-in-chief, commenting in "How CrossCheck can combat the perils of plagiarism": "t depends very much on whose text is reused and in which part of the paper. There's a big difference between similarities in the research methodology descriptions and the actual research findings.

What Content is iThenticate Using to Compare my Submitted Manuscript for Similarity?

iThenticate relies on an extensive and growing database of research documents from 3 sources, including premium scholarly publications, the Intenet Archive, and a global student papers database. (An updated description of these sources is available from iThenticate at and Databases Content  (PDF))

(1) CrossRef's database of journal articles, conference proceedings and books for which they have issued Digital Object Identifiers (DOIs). These research documents come from from leading scientific, technical and medical (STM) publishers who rely on CrossRef for their DOIs. As part of the agreement with CrossRef, these publishers have agreed to provide to iThenticate the full text of their documents so that the CrossRef portion of the iThenticate database continues to grow as more research is published daily around the world.

(2) Subscription content and research titles from major content providers including ProQuest, Ebsco, and other database vendors typically available through college libraries. Theses include in the ProQuest database are included in this portion, but it is important to note that an increasing number of top research universities (including Caltech, Stanford, UT Austin, Georgia Tech) no longer submit their graduate scholarship to ProQuest and are thus not included in iThenticate's similarity check.

(3) Web pages crawled by iThenticate's own search engine, with content dating back at least a decade and being updated daily.

it is important to keep in mind that iThenticate's repository is not complete -- the Similarity Report and Similarity Score reflect matches only to documents contained in iThenticate's repository.

Not Sure if Your Publisher is Basing Editorial Decisions on iThenticate Similarity Reports?

You may wish to check the Author Guidelines for the publisher or journal of interest to see if they mention iThenticate or CrossCheck or CrossRef Similarity Check.

The publisher website may include an iThenticate badge such as this:

iThenticate Button 1

For example, the Copernicus website at clearly indicates use of iThenticate.