Criterion 2 in the Vancouver Recommendations
Deciding what is sufficient to meet the first criterion requires both specific knowledge of the discipline and good familiarity with practices and customs in the area in question. This will naturally be open to discussion, and we will not go into further detail here. We are mainly concerned with problems that arise in connection with Criterion no. 2, even where there is agreement about who meets the requirements in Criterion no. 1. Here, it will be useful to see the issues in light of the dual purpose of the criteria: to ensure that nobody is unfairly excluded and nobody is undeservedly credited. Authorship is reserved for those who deserve to be credited for substantial contributions to the work, and at the same time also are in a position to be held accountable for the totality (1). Furthermore, it is underscored that the criteria should not be used to exclude colleagues from co-authorship by not inviting them to participate in the preparation of the manuscript and approval of the final version.
Anybody who meets the first criterion should thus be given the opportunity to meet the requirements in the others. However, this condition obviously implies that meeting the substantial requirement in no. 1, as well as the more formal requirements in nos. 2 and 3, is not sufficient for authorship.
Criterion no. 2 requires the authors to participate in the preparation of the article in a way that contributes to important intellectual content. But how can this concept be delimited? A reasonable interpretation, in light of the objective of the criteria, is that an author's contribution implies a systematic composition, made either in writing or through concrete contributions to the discussion. This can apply to the article itself, or as a minimum, to critical review of a draft that helps highlight the scientific content or idea of the article. Such a contribution can be made in writing or orally, initially or during the process, but it needs to appear as a sine qua non; without this contribution, the content of the article would have been different or of less intellectual value.
Having contributed only to the collection and/or processing of data would be insufficient, even for someone who has also read and approved the final draft
Thus, having contributed only to the collection and/or processing of data would be insufficient, even for someone who has read and approved the final draft. This interpretation of Criterion no. 2 will give rise to challenges for interdisciplinary research communities where there is an established practice of including everyone who has contributed substantially to data acquisition and analysis, but where a smaller group is charged with writing the article itself. Criterion no. 2 thus says that the authors are those who have contributed to the preparation of the article as such, either by writing (parts of) it or by giving critical input to the work on the manuscript. Irrespective of how this is done, through written comments or discussions, the group of authors must be able to give an account of the way in which each author has specifically contributed to the intellectual content of the article. Here, it will be insufficient to refer to acquisition or analysis of data that some of them have undertaken. It must also be possible to point to concrete, intellectually important contributions to the preparation of the article. When this requirement is not met, the appropriate form of credit will be a reference to research collaborators or recognition in the acknowledgements (2).