Scientific authorship: including a former lab member who collected (unused) pilot data?

Question

I am working on a manuscript of a project that I am first author on, and am wondering whether it is proper to include person X. X has been gone from the lab for 3 years, and none of her data is in the manuscript or really informed the conclusions. However, my experimental design (for one figure out of 8) is very similar to her original plan, although the analysis is different. It's not clear if the original idea was X's, or my PIs (it was a pretty natural extension from a paper we read in journal club). Any advice about whether X should be a coauthor? Does anyone have any examples of this happening, and what was the outcome from each perspective?

Update: thank you for all the input! To clarify: 1. My PI was actually the one who asked ME for my opinion in this situation - I think she was on the fence. But you're right that it is her job to make the final call, she was there when the original pilot experiments were performed.

2. The experimental tools were not new, they are common/published already. The details of the design (I.e. vary x in increments of 5) were the former student's

3. Looks like we are planning (at least at the conference stage, could always change when paper is closer to submission) towards not including X

Answer 1

There are two key questions, as I see it. The first is whether the experimental design you used was originated by the former student. If it was the PI's idea (or somebody else's), and the student merely implemented it, that the former student does not need to be an author. If, on the other hand, the apparatus and techniques were truly originated by the former student, there may be a strong case for making them an author. You should ask the PI specifically about who designed the experiment (as well as consulting them about the whether the previous student should be a coauthor; the PI is likely the best person to evaluate whether the student made a meaningful contribution to the current paper).

If it is established that the old student did originate the experimental arrangement, there is then a second question: Was this experimental design already used as the basis for a published paper with that student as an author? If there was already a paper on the older results, then the student has already received credit for designing the experimental setup. In that case, you can cite the older paper as originating the methodology, and the former student does not need to be an author on papers describing further developments made after they left.

Answer 2

You should ask your PI. Authorship conventions vary drastically between fields and the PI will know information about the following

(1) whether the experimental design was novel, and whether she designed the experiment or just performed it. (2) whether her data informed anything in your project (you said it didn't inform your results or analysis, but it could have informed other aspects [like what question to ask next], and it could have informed the PI in ways they have not told you) (3) Whether any of the above means authorship is conventionally expected in your field

A key point though, is whether her experimental design is published in a thesis, report, conference or separate paper. If it is, you quite likely could cite it and potentially not include her as an author (although you should still ask your PI about this). However, if it is not, then authorship could be warranted because you benefited from her experimental design which could be interpreted as a substantial intellectual contribution.

Answer 3

From what I read, you seem to describe a case about the limits of intellectual property, with particular emphasis to ownership of ideas from a previous student/researcher. I will tell you how a similar situation was handled by my former PI:

a) I designed (calculations, CAD, materials and equipment selection, etc) an experimental device needed to collect specialized measurements. I also chose and installed all the equipment (electronics/software) used during the measuring process as well as the analysis of the data. This was part of my work as a research assistant.

b) This equipment was used to collect data for my thesis, papers and publications.

c) Once I graduated, the equipment was given to a different student which used it to collect more data. This student has access to all the documents associated to the equipment. He has collected data and produced papers from this setup. However, he did not put my name in the documents. Although the design was my idea, it does not belong to me. The regulations of my University are clear about this.

Now to your case: Person X has not had direct contribution to your results other than similar ideas about how to proceed on certain topics or design a particular process. My suggestion is that you put his/her thesis as a reference, indicating clearly where the similarities occur. The name of person X should not appear as a co-author unless you are using data/results directly from his/her thesis. If this is your PIs idea, his/her name will be (most likely) on the manuscript as a co-author no matter what.