Deciding on who gets an authorship credit, and how they are ranked, is an important part of doing science responsibly. When scientists put in equal amounts of effort on a project it can be hard to decide who gets credit and how much. There is no perfect approach to setting up an author list. 

The International Committee of Medical Journal Editors (ICMJE), has developed authorship guidelines that are widely used. The rules say that to be listed as an author, each researcher must meet three key criteria: (1) they must have been involved in designing the project, collecting data or analyzing the results, (2) they must have participated in drafting or revising the manuscript, and (3) they must have approved the final, published paper. The Committee on Publication Ethics (COPE) recommends researchers to set up the author list prior to conducting experiments, and that the group revisits the author list during and after the project.

When researchers can't work out the author list, it is advised to bring in an unbiased third party to help make the decision. Authors can decide to share authorship, but sharing credit to broadly can be risky. It sometimes happens that authors get listed out of courtesy. Accepting courtesy authorship is risky. If the paper become famous, every author on the list gets to claim credit, but if the paper fails, everyone gets a share of the blame. If people do decide to get listed as a courtesy, they must have read the paper beforehand. It is advised to not let your name be put on the author list of a paper if you haven’t made a key contribution. It can also happen that people get authorship without their knowledge and permission. If that happens, people are advised to contact the editor of the journal to solve the issue.

When scientists are planning a project they should also find a way to describe everyone’s contribution. Stephen Kosslyn, a psychologist, has created a way to decide authorship by using those descriptions of contribution. He created a 1000-point system, in which every type of contribution holds a certain amount of points. To be listed as author one must have a minimum of 100 points. The ranks are determined by a person’s point total. If disagreement still occur, a third party decides how the points are assigned. However, with this method it rarely comes to that. Usually it is very obvious what the order is going to be.