Guide to Authorship Contributions

Authorship of articles is an important way in which the contribution of individuals to particular research is recognised and, equally, the proponents of particular views are identified; thus, authorship confers credit, but also implies responsibility.

Broad guidelines as to who should be included as an author are provided by the International Committee of Medical Journal Editors.

In practical terms, contributions should be measured against the ‘impact on the argument presented in the paper’. Ask the question “Would the paper have existed in this form if any individual hadn’t contributed?” A small contribution (the ‘killer’ idea) can have a big impact, and should be credited accordingly, as should multiple smaller contributions – such as performing a series of individual analyses. Note those who contribute to early stages of the research should automatically be invited to participate in the later stages of write-up and review.

All authors should be able to vouch for/defend the part of the paper they contributed to (which might only be a specific part in the case of e.g. data collection or provision).

We should make particular effort to recognise, where appropriate, contributions by early career researchers, those involved in scheme organisation, and others who might not normally be involved in manuscript preparation.

The scoring system is meant to provide a framework for assessing different contributions and points should be awarded on a sliding scale (i.e intermediate scores are allowable if useful). Anyone scoring 25 points or more should normally expect to be included as an author; others may be if this seems appropriate.

No scoring system can accommodate all situations (or solve all arguments); it provides a (hopefully helpful) starting point for discussion. In general, it is better to be inclusive and to discuss expectations at an early stage in order that everyone is clear about their role.

Conventions between fields, and between countries, vary sufficiently that it is hard to infer contributions directly from the author list, beyond the fact that the first author (usually, but not always) has either written (most of) the paper, or undertaken (most of) the analyses. Increasingly journals are asking for roles to be explicitly specified so that this may be clarified. As a starting point, on European ecological papers, the person who did most of the writing/analysis would normally be first author, the person who conceived/supervised the project (if different) would normally be last; with other authors should be listed in approximately decreasing rank of contribution (unless there are good reasons to do otherwise), and alphabetically by surname in the case of equal contributions. Where there are ‘equal’ first contributions, many journals allow “joint first authors” to be identified (or, equivalently, to indicate that authors contributed equally to the work).

Co-authorship scoring system

Intellectual input (planning/designing/interpreting)


No contribution 0
Involved in correspondence/general discussion 5
Contributing a specific idea 10
Contributing to/influencing multiple ideas 15
Designing the overall project plan/proposal 20

Practical input (data collection/storage/manipulation)


No contribution 0
Extracted data for a specific request 5
Developed coding/selection/manipulation to provide data 10
Collected some data presented in the manuscript 10
Collected most of the data presented in the manuscript 20

Analytic input


No contribution 0
Small amount of analysis under direct supervision 5
Provision of statistical advice 10
Most or all of the analysis, but under direct supervision 20
Developed and undertook with only advice as necessary 25

Literary input (contribution to first complete draft of manuscript)


No contribution 0
Provided comments on the manuscript 5
Contributed small sections (e.g. methods or particular discussion points) 10
Undertook a substantial edit (involving modification/addition of many paras) 20
Wrote all or most of the first draft 25

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