CASRAI Dictionary

Tag: degree of contribution

  • CRediT degree-of-contribution qualifiers: using lead, equal and supporting correctly

    Most researchers who have encountered the CRediT taxonomy know it as a list of fourteen contribution roles — Conceptualization, Methodology, Software, Investigation, Writing – original draft, and so on — that allows a paper to say who did what rather than relying on a bare author list. But there is a second dimension to CRediT that is less widely understood and frequently underused: the ability to attach a degree of contribution to each role. CRediT is not only about which roles a person played; it can also convey how much they contributed to each, through the qualifiers lead, equal and supporting. Used correctly, these transform a flat list of roles into a far more informative account of a collaboration. This article explains them, drawing on the CRediT extensions domain of the CASRAI Dictionary.

    The standard behind CRediT

    It is worth recalling that CRediT is not merely an informal convention but a recognised standard. It was formalised as ANSI/NISO Z39.104-2022, the standard maintained through the National Information Standards Organization (NISO). That formalisation matters: it gives CRediT a stable, authoritative definition that publishers, systems and institutions can implement consistently, rather than each interpreting the taxonomy in its own way. Part of what the standard defines is precisely the degree-of-contribution dimension — the provision that each role may carry a qualifier indicating the extent of a person’s involvement. The qualifiers are therefore an official part of CRediT, not an add-on, and understanding them is part of using the taxonomy as it was designed.

    What lead, equal and supporting mean

    The three degrees are straightforward in concept, and their value lies in applying them honestly. A contributor designated lead for a role had primary responsibility for that aspect of the work — they drove it, took the leading part, bore the main responsibility for it. A contributor marked equal shared responsibility for the role roughly evenly with one or more others; no single person led it, the work was genuinely joint. A contributor marked supporting made a real and acknowledged contribution to the role but in a secondary capacity, assisting rather than leading. The point of the qualifiers is to capture the texture of collaboration that a yes/no assignment misses. Two people might both be credited with Investigation, but if one designed and ran the experiments while the other assisted, “lead” and “supporting” convey that asymmetry truthfully, where listing both would imply a parity that did not exist.

    Why the qualifiers matter

    The degree qualifiers add value in several ways. They improve accuracy: a contribution statement that distinguishes who led from who assisted is simply a more truthful account of the work. They aid recognition: a researcher who led the methodology and another who supported it both deserve credit, but distinguishing the two does justice to each, and helps those reading the record — hiring panels, promotion committees, collaborators — understand the actual shape of someone’s contribution. And they support fairness in difficult cases. Where contributions are genuinely shared, the equal qualifier provides a recognised way to say so, which is particularly valuable for marking shared leadership of a role without forcing an artificial hierarchy. In each case, the qualifier carries information that the plain list of roles cannot, and that information is exactly what makes a contribution statement useful rather than merely present.

    How to apply them in a contributor statement

    Applying the qualifiers well is a matter of judgement exercised honestly. Some practical principles help:

    • Assign degrees role by role. A person’s degree can differ across roles — lead on Writing – original draft, supporting on Investigation. Consider each role on its own terms rather than assigning one overall level.
    • Reserve “lead” for genuine primary responsibility. If several people are all marked lead on the same role, the designation loses its meaning. Lead should identify who actually drove that aspect of the work.
    • Use “equal” when it is true, not as a courtesy. The equal qualifier is valuable precisely because it is accurate; applying it to smooth over differences that really exist undermines the honesty the system depends on.
    • Do not inflate “supporting” into more than it was, nor dismiss it as trivial. A supporting contribution is a real contribution, properly acknowledged; the qualifier honours it for what it was.
    • Agree the assignments among contributors. Degrees, like roles, should be discussed and agreed by the people involved, ideally early, to avoid disputes and to ensure the statement reflects a shared understanding.

    The limits and the discipline

    The qualifiers are powerful only if they are used with discipline. Their entire value rests on being applied truthfully; a contribution statement in which everyone is “lead” on everything conveys nothing, and one in which degrees are assigned to flatter rather than to describe is worse than none, because it dresses up inaccuracy as precision. The degrees are an invitation to be honest about the real distribution of work, not a set of titles to be distributed for diplomatic convenience. Used with that discipline, they let a contribution statement do justice to the genuine complexity of collaborative research; used carelessly, they merely add noise.

    A consistent vocabulary for contribution

    For degree qualifiers to mean the same thing across journals, institutions and reporting systems, the taxonomy and its qualifiers must be applied consistently — which is precisely what formalisation as ANSI/NISO Z39.104-2022 enables, and what a shared vocabulary sustains in practice. That consistency is what the CASRAI Dictionary supports: a shared vocabulary so that a role marked lead, equal or supporting is understood the same way wherever it is recorded, whether it travels through a publisher’s system, a repository or an institutional CRIS. CRediT’s roles tell the reader which parts of the work a contributor touched; the degree qualifiers tell them how much. Together, and used honestly, they turn the author list from a question into an answer — a clear, structured account, grounded in good authorship practice, of exactly who did what, and to what extent.

  • How to write a CRediT author statement: a step-by-step guide

    The CRediT author statement has moved from novelty to routine: a large majority of major publishers now ask for one at submission, and many will not advance a manuscript without it. Yet it is still frequently drafted in the last hour before submission, by one author, from memory. That is a missed opportunity, because a statement assembled carelessly does exactly what a contribution taxonomy is meant to prevent. This guide sets out a step-by-step method for producing one well. The authoritative how-to lives at how to write a CRediT author statement, and this article walks the same ground in practice.

    First, know what CRediT is — and is not

    Before assigning a single role, fix two facts in mind. CRediT is a controlled vocabulary of fourteen contributor roles, each with a canonical definition and a stable identifier, maintained as a NISO standard. It records what people did. It is not a definition of authorship, and it is not a scoring system. The decision about who qualifies as an author is made separately, under the ICMJE criteria in biomedical fields and equivalent norms elsewhere; CRediT supplements that decision and does not replace it. Conflating the two is the most common error in this area, and it is worth reading the full account of authorship and accountability alongside this guide.

    The fourteen roles fall into four loose functional groups that make a useful checklist: planning and design (Conceptualization, Methodology, Software); research and analysis (Validation, Formal analysis, Investigation, Resources, Data curation); communication (Writing – original draft, Writing – review & editing, Visualization); and management (Supervision, Project administration, Funding acquisition). The canonical definitions are set out at the CRediT roles, and you should assign against those definitions rather than against your intuition about what a role name implies.

    Step 1: list every contributor, then settle the author line

    Start with people, not roles. Write down everyone who contributed to the work in any way, including those who may end up acknowledged rather than authored. Then apply your field’s authorship test to decide who belongs on the author line. In biomedical research that is the ICMJE four criteria: substantial contribution to conception or design or to acquisition, analysis or interpretation of data; drafting or critically revising the work; final approval of the version to be published; and accountability for the work. Most publishers apply CRediT only to named authors, so settle the author line first.

    Step 2: assign roles to each named author against the canonical definitions

    Take each author in turn and ask, for each of the fourteen roles, whether they genuinely performed that contribution as the definition describes it. Some pointers that prevent common mistakes:

    • Investigation is performing the experiments or collecting the data — not the same as Data curation, which is annotating, cleaning, and maintaining the data for reuse.
    • Methodology is designing or developing the method; Software is writing the code that implements it. In some fields these overlap, but assign both only where both genuinely happened.
    • Writing – original draft is preparing the initial draft; Writing – review & editing is critical revision by members of the original research group. An author who only commented on a near-final draft did the latter, not the former.
    • Funding acquisition, Resources, and Supervision are legitimate roles, but on their own they may or may not meet the authorship bar in your field — record the contribution honestly and let the authorship test, not the role, decide.

    Be aware that even careful researchers given the same description sometimes disagree on which roles apply; the boundaries between adjacent roles are genuinely fuzzy. Treat the statement as an honest broad signal, not a precise measurement.

    Step 3: add the degree-of-contribution qualifier where it helps

    The standard supports an optional qualifier on each assignment — lead, equal, or supporting. It is not a percentage and it does not rank roles against one another; it distinguishes “I led this” from “I contributed to this.” Most published statements omit it because few publishers require it, but it is genuinely useful where several authors share a role: marking one author as lead on Writing – original draft and two as supporting conveys real information at almost no cost.

    Step 4: confirm with every author

    A contribution statement is a claim made on behalf of named people, so each named person should see and confirm their own roles before submission. This is not bureaucratic box-ticking. It is the step that catches the case where one author has, in good faith, attributed to themselves work that another person actually did — the failure mode that an honest taxonomy exists to surface. Circulate the draft statement; let each author correct their own line.

    Step 5: format it for the journal

    The conventional written form lists each author by name followed by their roles:

    Zhang San: Conceptualization, Methodology, Software. Priya Patel: Data curation, Writing – original draft. Erin Wright: Visualization, Investigation. Adam Lloyd: Supervision, Software, Validation. Maria García-López: Writing – review & editing.

    Many submission systems collect the same information through a structured form instead, which is better: a statement captured as structured metadata can propagate to Crossref and ORCID and be read by downstream systems, whereas a closing paragraph of prose cannot. Where the journal offers the structured route, use it. Where it only collects a narrative paragraph, write the paragraph above — but know that its value as machine-readable data is limited until the publisher’s plumbing catches up.

    Common pitfalls to avoid

    • Treating CRediT as the authorship test. It records contribution; it does not decide who qualifies as an author.
    • Claiming roles for acknowledged work. If a medical writer drafted the text or a technician ran the experiments, do not absorb their roles into an author’s line.
    • Over-assigning. Listing all fourteen roles for the senior author signals nothing. Assign only what was genuinely done.
    • Leaving author order to CRediT. CRediT does not encode author order; that is a separate decision your field’s conventions govern.

    Where shared vocabulary fits

    CRediT itself is settled; the live problem is that its real-world implementation is uneven, with many venues collecting only narrative paragraphs rather than structured metadata. A shared, federated vocabulary that defines the roles consistently and points back to NISO for the standard is what lets a statement written for one system mean the same thing when read by another. Supplying that definitional layer is the role the CASRAI dictionary is designed to play; the contributor-roles vocabulary sits in the CRediT extensions domain.

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