How to reference your own dataset in a figure or table caption?

Question

I made several plots and figures. About 20% of data I used to make a plot came from papers of other people, which I'm surely going to cite in a common manner. But the other 80% percent of data I collected on my own during the research, so I'd like to point it out in the figure's caption (otherwise a person who reads my article would have gone to the cited paper and found there only 20% of data).

What is the proper way of doing this? Should it look like that (example picture is taken from here):

Fig. 1. Dependence of Y on X within different groups [123, own dataset].

where:

• [123] is the ordered number of an external dataset reference in the reference list;
• [own dataset] - an attempt to reference my own data.

Answer 1

I assume you describe the dataset elsewhere in the paper (including data collection methods, or, if you're using and analyzing a data set published elsewhere, at minimum the data analysis methods) like Massimo Ortolano suggests. If feasible, I would suggest clearly labeling the legend entries to make the data sources clear, e.g. instead of "Group 1", "Group 2", and "Group 3" you might have "Isaev (2003)", "Someone else (2012)", and something like "This work" (or "this study"). This way the fact that the data comes from different sources gets communicated clearly even if the figure is displayed without the caption, which might well happen in talks etc.

Often more informative labels are useful, e.g. if there are datasets collected using different techniques or multiple datasets from the same source. I would slightly caution against legend entries using numerical references such as "Isaev [3]", where [3] is some entry in the list of references. I've done so in the past, and unless you automatically generate the figure the numbers can easily end up pointing to the wrong references as as citations are changed in the main paper. It is better to include such direct citations in the caption, just as you suggest. However, there is little reason to put something like "[own dataset]" in the caption, especially if you have "This work" in the legend. You may well want to devote some space in the caption contrasting your and others' results, for which phrases such as "our results" may be useful, but generally what isn't explicitly referenced is assumed to be your original work. At least, that's the case if it is a reasonable assumption in light of the rest of the work.

Answer 2

I suggest you to have a section at the beginning in which you describe the datasets used in the work, referencing other work's datasets and presenting your own datasets with the methodology used to collect them.

Label or number each dataset, so that you can then later refer to the datasets in figures and tables. For instance, your caption could become

Datasets D2 and D5.

or

Datasets D2 [123] and D5.

Answer 3

Unless there is a strong reason for doing otherwise, I would suggest that you make your data available on a public (open) data repository such as figshare. The dataset can then be referenced with an appropriate URL or DOI, in addition to describing your own data exactly as the other answers suggest.

I mention figshare here only as an example. There are many other excellent open data repositories that you could consider.