Determining first authorship for a shared project

Question

There is a project (STEM field, R1 university in the United States) on which four graduate students have been working for approximately one year. Although all members joined the project at the same time, one person, who is a senior student, was training the others for the first month. The group does not have a distinct division of tasks: after the initial training period, all members have worked closely, sharing equal responsibility for performing lab work, studying literature, analyzing data, and contributing hypotheses. None of them has been part of other simultaneous projects for the work's full duration.

Much experimental and analysis work remains before they start writing a paper summarizing their results, and the group has not discussed authorship yet. I would like to know how authorship for such a project is determined.

Should a sole first-author position automatically go to the senior student who trained the others in the beginning? Should co-first authors be designated based on a discussion of whose contributions were most significant? Should author order be determined based on time committed to the project? Or, since all members have been working full-time on this project, does that mean they should all automatically be made co-first authors? Are there any other factors that would need to be considered in such a situation?

You may assume that all potential journals for the publication allow shared authorship, and the students' research advisor will be the corresponding author.

Answer 1

I assume the question is for a field where authorship is based on contributions; see this question for a discussion of conventions in various fields.

the group has not discussed authorship yet

Then the group would benefit from going ahead and discussing it. Waiting until the end and everyone getting different ideas risks causing disappointment, resentment, and conflict. This is perhaps especially the case when you have coauthors at different stages, where one of them might need first authorship more than the others for career or graduation reasons, and the project is started with that in mind. Better if junior student #3 knows that this is the plan from the start, and determines their investment in the project accordingly.

Should a sole first-author position automatically go to the senior student who trained the others in the beginning?

Not automatically, no. Training someone else does not even automatically qualify for coauthorship. On the other hand, perhaps that senior student didn't just provide standard training on how to use a piece of equipment or software, but also designed a suitable approach and analysis protocol, which could be a significant contribution.

Should co-first authors be designated based on a discussion of whose contributions were most significant?

This is confusing. Co-first authors usually come with a footnote stating something to the effect that "These authors contributed equally". If you have a clear ranking of whose contributions were more significant, why are you considering joint first authorships?

Should author order be determined based on time committed to the project?

Absolutely not. This would mean that someone who didn't contribute anything of value to the paper could claim first spot just because they had time to waste, while another author who had all the ideas and did all the work could be punished for working effectively.

Or, since all members have been working full-time on this project, does that mean they should all automatically be made co-first authors?

Again, not necessarily.

Are there any other factors that would need to be considered in such a situation?

The most important factor is intellectual contributions. You say that everyone is responsible for contributing hypotheses, but whose ideas are actually going paying off? This can be on different fronts, including experimental design, approach to data analysis, modeling, interpretation etc. Which contributions are producing the most scientific value in the project? It's certainly possible that the individuals contributing can't be clearly separated, in which case shared first authorship is recommended.