Procedures for the submission and publication of supplementary data, or supplementary information (SI) may differ from publisher to publisher. SI is defined by Nature Publishing Group (Nature) as:
‘peer-reviewed material directly relevant to the conclusion of a paper that cannot be included in the printed version for reasons of space or medium, for example datasets, video or sound files.’
When contacting publishers it is important to find out their policies on supplementary data, i.e., the platforms they use for submission and publication, and the privacy settings they prefer. Even the format in which SI is initially submitted may be subject to specific guidelines. For example, Nature stipulates that ‘flat’ SI such as methods, tables, and notes should be submitted in PDF format, as does the British Medical Journal (BMJ), while SI which may need editing, such as data, needs be submitted separately.
Journals may require datasets to be submitted along with other types of SI, although some journals, like Nature, offer some flexibility; datasets are sometimes submitted as an SI file as above, or submitted via a repository. Some repositories make it possible for anonymous peer-review ahead of publication but this is often left to the author to communicate with the repository. Indeed, all communication with the repository may be the author’s responsibility, so it is important to ensure that the dataset is made publicly available at the correct time (click here for suitable repositories for different types of datasets.
Publishing groups or journals, such as BMJ, may offer help to make datasets available online. Alternatively, it is recommended that online tools are used to help make datasets more widely accessible online, thus increasing citations of the manuscript. Deposited datasets can be provided with Digital Objective Identifiers (DOIs) for ease of citation, and it may be beneficial to publish a Data Descriptor.
Online publications for descriptors, such as Nature’s Scientific Data, provide a platform for data to be re-used in future research, and help authors to be as transparent as possible in their work. Journals may vary in their preference for the publication of Data Descriptors; some may be happy for the Data Descriptor to be published ahead of the manuscript and others may wish for it to be published simultaneously.
Supplementary files are not always edited or sent to typesetters along with the rest of the manuscript so it is important to check all supplementary files carefully and ensure they adhere to journal style.
For more information about Nature and BMJ’s guidelines discussed here, please visit the following websites: