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Dictionary termTrack AProposedv2026.1

Contributor Role Ontology (CRO)

The Contributor Role Ontology (CRO) is a formal OWL ontology, developed by the data2health consortium and published via the OBO Foundry and NCBO BioPortal, that extends CASRAI's CRediT (Contributor Roles Taxonomy) into a machine-reasonable class hierarchy. Where CRediT defines a flat, non-hierarchical list of 14 contribution roles (Conceptualization, Data curation, Writing — original draft, and so on) intended for a human to pick from a fixed list on a manuscript submission form, CRO represents each role — plus additional roles beyond CRediT's 14 — as a formally defined ontology class with a unique persistent identifier in the form CRO:NNNNNNN, explicit parent/child relationships, and logical axioms suitable for automated reasoning and integration into knowledge graphs and biocuration systems.

ByCASRAI Editorial Board
· Last updated 6 Sept 2026
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Examples

Worked examples

  • Is an instance

    A biocuration database recording who did what on a genomics dataset uses CRO class identifiers instead of free-text or a flat taxonomy label, so contribution records can be linked and reasoned over alongside other OBO Foundry ontologies used elsewhere in the same knowledge graph.

  • Is an instance

    A linked-data or RDF metadata system representing contributor roles adopts CRO's dereferenceable, persistent class URIs rather than plain-text CRediT role names, because CRO classes resolve to a stable identifier that other systems can point to directly.

Counter-examples

Looks similar, but isn't

  • Not an instance

    A journal's "Author Contributions" statement listing "J.S.: Conceptualization, Data curation" using the plain CRediT role names is using CRediT, not CRO — writing out CRediT category names in prose does not invoke CRO's ontology infrastructure. The vast majority of researcher-facing CRediT use (manuscript submission forms, published author-contribution statements) is CRediT alone; CRO is infrastructure for systems that need formal ontological reasoning over contribution data, not a researcher-facing relabeling of CRediT.

Editorial commentary

The Contributor Role Ontology (CRO) is a formal OWL ontology, developed by the data2health consortium and published through the OBO Foundry and NCBO BioPortal, that extends the CASRAI-originated CRediT (Contributor Roles Taxonomy) into a machine-reasonable class hierarchy for use in biocuration, linked-data, and knowledge-graph systems.

CRO is not CRediT — the distinction that matters

CRediT defines 14 flat, non-hierarchical contribution roles that CASRAI has stewarded since 2014 and that are now published as the full ANSI/NISO Z39.104-2022 standard, with NISO holding primary stewardship and CASRAI operating as a federation partner. CRediT is what appears on a manuscript submission form and in a published “Author Contributions” statement — see the comparison of CRediT and the NISO Contributor Roles Taxonomy for how those two names refer to the same standard.

CRO is a separate piece of infrastructure that builds on CRediT rather than replacing or competing with it. Its own documentation describes it as expanding CASRAI’s Contributor Roles Taxonomy — it takes CRediT’s role list as a starting point and adds the formal semantic-web machinery (class hierarchy, persistent CRO:NNNNNNN identifiers, logical axioms) that CRediT itself was never designed to provide. CRediT is deliberately simple and human-facing; CRO is deliberately formal and machine-facing.

Why the ontology layer exists

A flat taxonomy like CRediT works well for a human filling out a submission form, but doesn’t, on its own, let software reason about contribution roles the way it can reason over other structured biomedical and scientific data — for example, linking a contribution record to a specific research object, or querying “which roles are more specific than Data curation” across a knowledge graph. CRO’s OBO Foundry membership means its terms are designed to interoperate with the wider ecosystem of biomedical and scientific ontologies (each CRO term carries a persistent, dereferenceable identifier that other ontologies and databases can reference directly), which a plain-text taxonomy cannot offer.

Related terms

Also known as

Contributor Role Ontology

Machine-readable encodings

Use in your systems

JATS XML <role> element
xml
<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="Contributor Role Ontology (CRO)"
      vocab-term-identifier="https://casrai.org/dictionary/term/contributor-role-ontology-cro" />
Schema.org DefinedTerm (JSON-LD)
json
{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/contributor-role-ontology-cro",
  "name": "Contributor Role Ontology (CRO)",
  "identifier": "https://casrai.org/dictionary/term/contributor-role-ontology-cro",
  "description": "The Contributor Role Ontology (CRO) is a formal OWL ontology, developed by the data2health consortium and published via the OBO Foundry and NCBO BioPortal, that extends CASRAI's CRediT (Contributor Roles Taxonomy) into a machine-reasonable class hierarchy. Where CRediT defines a flat, non-hierarchical list of 14 contribution roles (Conceptualization, Data curation, Writing — original draft, and so on) intended for a human to pick from a fixed list on a manuscript submission form, CRO represents each role — plus additional roles beyond CRediT's 14 — as a formally defined ontology class with a unique persistent identifier in the form CRO:NNNNNNN, explicit parent/child relationships, and logical axioms suitable for automated reasoning and integration into knowledge graphs and biocuration systems.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/credit-extensions#set",
  "url": "https://casrai.org/dictionary/term/contributor-role-ontology-cro",
  "alternateName": [
    "Contributor Role Ontology"
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "publisher": {
    "@id": "https://casrai.org/#organization"
  },
  "author": {
    "@id": "https://casrai.org/#editorial-team"
  },
  "datePublished": "2026-08-22T09:45:28",
  "dateModified": "2026-09-06T18:02:58",
  "inLanguage": "en-GB",
  "isAccessibleForFree": true
}

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