While gearing up for the Dryad member meeting (to be held virtually on 24 May – save the date!) and publication of our annual report, we’re taking a look at last year’s numbers.
2015 was a “big” year for Dryad in many respects. We added staff, and integrated several new journals and publishing partners. But perhaps most notably, the Dryad repository itself is growing very rapidly. We published 3,926 data packages this past year — a 44% increase over 2014 — and blew past the 10,000 mark for total data packages in the repository.
Data package size
Perhaps the “biggest” Dryad story from last year is the increase in the mean size of data packages published. In 2014, that figure was 212MB. In 2015, it more than doubled to 481MB, an increase of a whopping 127%.
This striking statistic is part of the reason we opted at the beginning of 2016 to double the maximum package size before overage fees kick in (to 20GB), and simplified and reduced our overage fees. We want researchers to continue to archive more (and larger) data files, and to do so sustainably. Meanwhile, we do continue to welcome many submissions on the smaller end of the scale.
Distribution of Dryad data package size by year. Boxplot shows median, 1st and 3rd quartiles, and 95% confidence interval of median. Note the log scale of the y-axis.
In 2015, the mean number of files in a data package was about 3.4, with 104 as the largest number of files in any data package. To see how times have changed, compare this to a post from 2011 (celebrating our 1,000th submission), where we noted:
Interestingly, most of the deposits are relatively small in size. Counting all files in a data package together, almost 80% of data packages are less than one megabyte. Furthermore, the majority of data packages contain only one data file and the mean is a little less than two and a half. As one might expect, many of the files are spreadsheets or in tabular text format. Thus, the files are rich in information but not so difficult to transfer or store.
We have yet to do a full analysis of file formats deposited in 2015, but we see among the largest files many images and videos, as would be expected, but also a notable increase in the diversity of DNA sequencing-related file formats.
So not only are there now more and bigger files in Dryad, there’s also greater complexity and variety. We think this shows that more people are learning about the benefits of archiving and reusing multiple file types, and that researchers (and publishers) are broadening their view of what qualifies as “data.”
Download counts
So who had the biggest download numbers in 2015? Interestingly, nearly all of last year’s most-downloaded data packages are from genetics/genomics. 3 of the top 5 are studies of specific wild populations and how they adapt to changing circumstances — Sailfin Mollies (fish), blue tits (birds), and bighorn sheep, specifically.
Another top package presents a model for dealing with an epidemic that had a deadly impact on humans in 2015. And rounding out the top 5 is an open source framework for reconstructing the relationships that unite all lineages — a “tree of life.”
In 5th place, with 367 downloads:
- Drake JM et al. (2015) Ebola cases and health system demand in Liberia. PLOS Biology 13(1): e1002056.
In 4th place, with 601 downloads:
- Hinchliff CE et al. (2015) Synthesis of phylogeny and taxonomy into a comprehensive tree of life. Proceedings of the National Academy of Sciences of the United States of America 112(41): 12764–12769.
In 3rd place, with 1,324 downloads:
- Kardos M et al. (2015) Whole-genome resequencing uncovers molecular signatures of natural and sexual selection in wild bighorn sheep. Molecular Ecology 24(22): 5616-5632.
In 2nd place, with 1,868 downloads:
- Class B, Brommer JE (2015) A strong genetic correlation underlying a behavioural syndrome disappears during development because of genotype-age interactions. Proceedings of the Royal Society B 282(1809): 20142777.
- Article: http://dx.doi.org/10.1098/rspb.2014.2777
- Data: http://dx.doi.org/10.5061/dryad.443g2 (one of the 2 data files in this package is embargoed until June 2016)
And this year’s WINNER, with 2,678 downloads:
- Nunez JCB et al. (2015) Population genomics of the euryhaline teleost Poecilia latipinna. PLOS ONE 10(9): e0137077
The above numbers are presented with the usual caveats about bots, which we aim to filter out, but cannot do with perfect accuracy. (Look for a blog post on this topic in the near future).
As always, we owe a huge debt to our submitters, partners, members and users for supporting Dryad and open data in 2015!