CRediT Author Contributions: Assigning the 14 Roles Without a Lab Dispute.

CRediT, the Contributor Roles Taxonomy, is a standardized list of 14 roles that describe what each author of a paper actually did: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, and Writing – review & editing. The taxonomy was formalized as ANSI/NISO standard Z39.104-2022, and journals such as PLOS ONE now collect these roles as required submission metadata rather than optional courtesy text. Assigning them takes twenty minutes when everyone agrees on who did what. The rest of this post is about getting to that agreement.

Why is an author contribution statement required?

Because at many journals it is enforced at submission, not requested afterward. PLOS ONE's guidelines state the rule plainly: "Provide at minimum one contribution for each author in the submission system using the CRediT taxonomy."

Two details in that sentence deserve attention. First, "at minimum one" means an author with an empty contribution field blocks your submission. Second, "in the submission system" means this is structured data the journal stores and publishes with the article, not a paragraph you can fudge. PLOS also requires that authors meet authorship criteria modeled on the ICMJE recommendations, the standards body whose definition of authorship most biomedical journals follow. The contribution statement is where those two policies meet: it is the public record of why each name on the byline deserves to be there.

What do the 14 CRediT roles mean in plain language?

Each role names one kind of work, and an author can hold several. Here is each role with the official definition compressed into one line.

• Conceptualization: forming the research goals and aims. The person whose idea it was.
• Data curation: annotating, cleaning, and maintaining the data so it can be used and reused.
• Formal analysis: applying statistical, mathematical, or computational techniques to the data.
• Funding acquisition: securing the financial support for the project.
• Investigation: performing the experiments or collecting the data and evidence.
• Methodology: designing the methodology or building the models.
• Project administration: coordinating the planning and execution of the research activity.
• Resources: providing materials, reagents, samples, patients, instruments, or computing resources.
• Software: writing, implementing, and testing the code and algorithms.
• Supervision: oversight and leadership of the research, including mentorship.
• Validation: verifying that results and outputs replicate and reproduce.
• Visualization: preparing the figures and data presentation.
• Writing – original draft: producing the first draft, including substantive translation.
• Writing – review & editing: critical review, commentary, or revision by members of the research group.

The taxonomy draws distinctions that everyday lab language blurs. Investigation and Formal analysis are separate roles, so the student who ran the assays and the postdoc who ran the regressions each get named for their own work. Methodology is distinct from Investigation: designing the experiment and performing it are different contributions. And the two writing roles split the person who produced the draft from the people who improved it, which matters more than any other line when disputes start.

How do five authors actually split the roles?

The typical pattern: the first author carries the draft and the hands-on work, the analyst carries the numbers, and the principal investigator carries supervision, funding, and administration. Here is a worked statement for a five-author study, with initials the way most journals print them.

S.A. (PhD student, first author): Conceptualization, Methodology, Investigation, Data curation, Visualization, Writing – original draft. She proposed the study within the lab's program, designed the protocol with her supervisor, collected the data, built the figures, and wrote the draft.

K.M. (postdoc): Formal analysis, Software, Validation, Writing – review & editing. He wrote the analysis code, ran the models, re-ran them on a holdout to confirm the results held, and revised the draft.

N.R. (research assistant): Investigation, Data curation. She ran half the data collection sessions and maintained the dataset. Two roles are enough. Nothing obliges you to pad her line.

J.W. (collaborator at another institution): Resources, Writing – review & editing. His lab supplied the reagent panel, and he commented on two drafts.

H.N. (principal investigator): Conceptualization, Supervision, Project administration, Funding acquisition, Writing – review & editing. She shaped the research aims, oversaw the work, managed the project, and won the grant.

Read that statement the way an editor would. Every author has at least one role, satisfying the PLOS ONE rule. The first author's line explains why she is first. The PI's line is long but contains no claim on Investigation or Formal analysis, because she did neither, and her co-authors know it. If you want statements in this exact format ready to adapt, the copy-ready CRediT statement examples cover single-author papers, equal-contribution pairs, and larger teams.

What about shared roles, honorary authors, and role inflation?

Shared roles are normal and expected. Three authors under Conceptualization is an ordinary statement, not a compromise. The taxonomy caps nothing.

Honorary authorship is the harder conversation. CRediT describes contributions; it does not define authorship. That job falls to the ICMJE criteria, which require substantial contribution to the work, participation in drafting or critical revision, approval of the final version, and agreement to be accountable, all four at once. Under those criteria, providing funding, collecting data, or general supervision alone does not qualify someone for authorship. So a department head whose only honest CRediT line would be Funding acquisition belongs in the acknowledgments, not the byline. The taxonomy makes this visible, which is precisely why some senior colleagues dislike it.

Role inflation is the quieter failure. It shows up as every author claiming Conceptualization, or a co-author who attended two meetings listed under Methodology. Resist it, because the statement is published, and readers who know the team can tell. A short, accurate line reads as confidence. A padded one invites the exact dispute the taxonomy exists to prevent.

How do you keep the statement consistent with the rest of the submission?

Check three points of agreement before you submit: the statement, the byline, and the cover letter must name the same people doing the same things. Initials in the statement must match the author list exactly, in the same order, with no one missing. If your cover letter says the first author led the analysis but the statement assigns Formal analysis to someone else, an editor will notice the mismatch. The same goes for the metadata fields in the submission form, which is why contribution roles sit alongside file formats and declarations on any serious first-submission checklist. These cross-document contradictions are exactly the kind of thing a rules-based manuscript review surfaces before an editor does.

One last practical habit: draft the statement early, circulate it to all co-authors, and get explicit sign-off in writing before submission. Every author will be asked to approve the final version anyway. Settling the roles while the work is fresh takes one email. Settling them after acceptance, with a deadline running, takes a mediator.