Co-authorship can be a source of frustration and conflicts. It is important to decide which co-authors to include and how the co-authors will contribute already at the beginning of the publication process. In addition, the co-authors should discuss this again when the manuscript is almost ready to be published. There are very few laws and regulations regarding co-authorship. The Vancouver recommendations is one of the few guidelines we have, and to a great extent, it is up to the co-authors to reach an agreement if a conflict should arise.

Here you will find summarized the most important things to keep in mind when publishing a paper with other scientists.

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Criteria for co-authorship

Being a co-author says nothing about the size of the contribution of the co-author in question. Therefore, several journals have recently started collecting information about the contributions of the respective co-authors of the paper to be published. If you are planning to publish in a journal that does this, you will be asked to give information about the contributions of the respective co-authors during the submission process, and this information will most likely be published alongside with the paper.

If you are a PhD student at NTNU, and you are publishing a paper which will later be included in your PhD thesis, you are responsible for collecting information about the co-authors’ respective contributions yourself (for more information – see separate paragraph below).

There are very few traditional rules regarding co-authorship. The closest we get are the Vancouver recommendations, which describe the role and the responsibilities of a co-author. Even though the Vancouver recommendations is not a law, NTNU urges its employees to follow them. According to the Vancouver recommendations, four criteria must be fulfilled for someone to qualify as a co-author of a paper:

  1. The person in question must have made a substantial contribution to the conception or design of the work; or to the acquisition, analysis, or interpretation of data for the work.
  2. She or he must have been involved in drafting the work or revising it critically for important intellectual content.
  3. She or he must have approved the version of the manuscript to be published.
  4. She or he must agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. In addition to being accountable for the parts of the work he or she has done, an author should be able to identify which co-authors are responsible for specific other parts of the work

According to the Vancouver recommendations, all the criteria above must be fulfilled for someone to qualify as a co-author. And vice versa – if someone fulfils all the criteria above, they should be included as a co-author.

In some cases, someone might fulfil one, two or three of the criteria above, but not all four of them. I such cases, the Vancouver recommendations recommend that they are acknowledged for their contributions in the paper, but that they should not be a co-author.

Read more about the Vancouver recommendations

It is not the journal’s responsibility to make sure that all the co-author of a paper being submitted to them meets all the criteria of the Vancouver recommendations. That should be done by the co-authors themselves. If possible, the co-authors should also agree on what their contributions to the paper will be before the work starts, and it should also be discussed who will be a co-author, and who should be acknowledged instead. By doing this, conflicts will be more easily avoided during the writing or the submission process.

In certain cases, the journals have their own rules and guidelines regarding the list of co-authors, and this should always be checked for the journal you have planned to publish your research in.

There are different practices of co-authorship within different fields:

In which order should the co-authors be listed?

The order of the co-author list is another possible source of conflicts. There are few written rules concerning this topic, but many unwritten ones. How the co-authors should be listed may vary from one field to another.

Most fields agree that the co-author who made the largest contribution to the paper should be listed first. Within certain fields, it is also common that the co-author who made the second largest contribution is the last author. In many cases, the last author is a group leader, or in case the first author is a PhD student – an advisor, but this is not a rule.

When publishing a paper with several authors, one of these should also be listed as corresponding author. Often, there are two corresponding authors when a paper is published – one before and one after publication.

The corresponding author before publication is the co-author who submits the manuscript. This co-author is also responsible for all correspondence with the journal, and for making sure the reviewers get an answer to all questions they might have during the review process.

The corresponding author after publication is the co-author listed as corresponding author on the title page of the submitted manuscript. This co-author is responsible for answering questions and requests from the public and the research community after publication.

When a PhD student publishes a paper, it is common that the PhD student him/herself is the one to submit the manuscript and to be responsible for correspondence with the journal during the submission and review process. However, it is rather unusual for a PhD student to be listed as corresponding author in the paper. The one being listed as corresponding author in the paper should preferably be someone with a permanent position, who will be available for answering questions also several years after the paper has been published.

The Vancouver recommendations do not say anything about who has the right to be last author or corresponding author. This, the co-authors must agree on themselves. The last author and the corresponding author is often the same person. However, this is not a written rule, and if it is more convenient, a co-author that is not the first or the last author, could perfectly well be listed as the corresponding author.

Doctoral thesis - declaration of co-authorship

If you are writing a doctoral thesis containing articles with co-authors, your co-authors must hand in signed declarations of co-authorship. The declaration should contain a description of your and the co-authors' contribution to the article. It is of particular importance that your independent contribution can be identified. The declaration includes consent to the article being included in your thesis.

Declaration of co-authorship (pdf) | Declaration of co-authorship (doc)

Useful links about authorship


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