The use of persistent identifiers (PID) is a core requisite for making research data accessible and fulfilling the FAIR principles. The goal is to make data and metadata easy to find, and also to ensure that it is possible to grasp the relation between research data, connected publications, authors and originators.
A persistent identifier (PID) is a type of metadata that provides material with a unique tag that remains the same over time – even if the material has been moved to another storage solution or website.
A PID is used to make it possible to find data and metadata, even when access to the actual data is restricted in some way. It is also a fast way to determine whether similar entries in registries, catalogues or reference listings point to
one and the same material
different editions or versions
A PID is also used to connect research data to the resulting research articles and other related publications. They are important to provide a coherent description of the research process behind the published results. By using a PID it is possible to connect several different publications to a data source, and thereby present a coherent view of how the source has been used over time and also how it may have been combined with other data sources.
Since the construction of a PID follows a predictable format, PIDs are machine readable, that is to say, a PID can be used to connect information without human intervention.
There are several different kinds of PID. Some of the more commonly used are DOI and URN.
DOI (digital object identifier)
A DOI (digital object identifier) is a widely used form of PID that doubles as a link to the material. A DOI consists of letters and numbers connected to a prefix to form a link. The DOI link is persistent and does not change over time.
Always include a DOI when referencing material. It is important to provide easy and direct access to the corresponding and correct information and material. As an originator it is important to ensure that the DOI of both the published article and the data is made visible alongside other information used to reference your work. This applies to both digital and printed formats.
Each data set registered with the Swedish National Data Service (SND) is assigned a DOI as part of the process. A DOI through the SND is administered by Data Cite.