When selecting a method of data sharing, there are a number of things to think about:
- Ease of data discovery
- Ease of data access
- Sustainability of data sharing solution
The ideal data sharing solution makes it straightforward for interested parties to find out about the data and to acquire a copy, and will ensure that the data remains available long into the future.
Whichever method is adopted, it is good practice for research publications which make use of the data to include a data availability statement. This is a brief note which either indicates where and how the relevant data can be accessed, or if some or all of the data is not available, explains why this is.
The pros and cons of some common methods of data sharing are discussed below. Further information can be found in the Options for preserving your data section of the Post-project preservation page: a number of the options listed there can be used for sharing data.
Data archives and repositories
One of the best methods of making data available for reuse is to deposit a copy in a specialist archive or repository. Archives exist for the specific purpose of preserving and sharing data, and as such, they are well equipped to make data discoverable, accessible, and sustainable.
Data archives are covered in more detail in the How to preserve your research data section of the Post-project data preservation page.
Re3data and FAIRsharing both maintain extensive catalogues of data archives. Oxford has its own institutional data archive, ORA-Data.
Many data archives are able to apply access controls to data deposits, and hence may be a good option for data which is not suitable for completely open sharing. This is covered in the next section below.
Other institutional services
Oxford's Sustainable Digital Scholarship service offers a Figshare-based platform designed for sharing research data. As the name suggests, it is designed to provide a long-term home for data, and ensure that it remains available well into the future.
General repositories and online sharing platforms
A number of services exist with the goal of making it easy to share research material (including but not limited to data) online. These may be publicly-funded services or commercial ones, and include Zenodo, OSF, and the main Figshare service (as distinct from Oxford's Figshare-based SDS).
These platforms vary a good deal, so it's important to check the terms and conditions carefully. They can provide a quick and convenient way of making data and other materials available, but data may not be as easily discoverable, and sustainability is not always guaranteed. They are also generally less likely to offer active curation of data or access controls than specialist repositories or institutional services.
If your research project has a website, it may be appropriate to host a copy the data there. This can be an effective way of sharing the data with a wider public, and may allow you to offer features that would not be available via a data archive, such as a custom search interface.
However, it is not advisable to rely on this as the sole method of making data available for the long term. Maintaining a website after a project concludes presents a number of challenges: funding bodies are generally reluctant to cover costs incurred after the end of the grant period, and project team members are likely to move on to other endeavours, and hence it is hard to predict how long a project website will remain viable for. If at all possible, a project website should therefore be seen as an additional method of sharing data alongside depositing a copy in an archive, rather than as an alternative to it.
Supplementary material to a journal article
In some fields, researchers may provide data files to be published alongside the journal article which presents the conclusions drawn from the data. This makes it very easy for readers to access the data, and has the advantage of presenting it in context. If the journal is a well-established one, it is also likely that the data will remain available for a considerable period of time (though it is worth checking the journal terms and conditions to see whether this is guaranteed).
However, there are once again reasons not to rely on this as the sole method of data sharing. While making the data available in this way is convenient for readers, it may be harder for other interested parties to discover the data. Additionally, the data relevant to a particular article will frequently only be a subset of the data produced by a research project. Where possible, it is therefore good practice also to deposit a fuller version of the dataset in a suitable archive.
Data available on request
It has been common in the past for researchers to add a note to research publications saying that data is available on reasonable request from the authors. However, this is not an ideal method of sharing data: it relies on potential reusers being able to contact the original researchers, which may be difficult if some time has passed and contact details have changed.
Even if the data is very sensitive, and a custom data sharing agreement would be required for any reuse, it is better if possible to have this process mediated by a specialist archive, rather than placing the responsibility on individual researchers. Some archives have processes in place for relaying requests back to data creators when necessary, and it may be possible to reach an agreement in advance about what action (if any) should be taken if the data creators cannot be located.
If no other sharing solution is viable, making the data available on request is preferable to not making it available at all, but it should nevertheless be viewed as a last resort, and only be adopted once other possibilities have been exhausted.