NARCIS enriched with the first results of a PID-Graph!

13 January 2020

Within FREYA, a European funded project, DANS has examined how a PID-Graph can be constructed by connecting Persistent Identifiers (PID) to each other.

PIDs are identifiers that can uniquely identify an object and keep the location of this object on the internet persistent. Naturally, NARCIS itself already contains many relationships between PIDs, because PIDs are included in the metadata, for example: publications contain PIDs such as DOI, Handle, ISBN or URN. Researchers often communicate with their ORCID, ISNI, ResearcherID or DAI (Digital Author Identifier). In the FREYA project, however, efforts have been made to make even more PIDs accessible and to integrate them into NARCIS. In this way, organizations can now also be unambiguously identified by a PID, for example a ROR, GRID or ISNI. But PIDs for grants and other digital objects can also be considered. In NARCIS, these PIDs are connected to each other, creating a so-called PID-Graph.

But many of these relationships are also present in other information portals. Within FREYA it has been investigated whether NARCIS can be enriched with relationships between PIDs that are located in these other information portals. DANS has written a piece of software that extracts a specific ORCID from NARCIS, goes to and retrieves all PIDs that are connected to this ORCID and compares it with the PIDs within NARCIS. In this way, additional relationships can be established between, for example, DOIs of publications present in NARCIS and a specific researcher. The NARCIS PID-Graph icon is always next to this link so that it is clear that the relationship has been obtained by a third party.

A good example is Spinoza winner Sinninghe Damsté. NARCIS was first able to link 580 publications to this researcher through a Digital Author Identifiers (DAI) that had already been included in the metadata by various organizations. Yet NARCIS contained many more publications where he is mentioned as an author, but these publications do not contain a person identifier in the metadata. By retrieving the DOIs of its publications from, NARCIS can now link these publications and expand the list of publications to 895. Other personal identifiers such as ResearcherID are also retrieved and linked to the existing NARCIS data.

This is only a first step. There are many more options for linking scientific information based on PIDs. NARCIS already links a DOI to services such as Altmetric and Unpaywall. Altmetric provides an overview of citations on Social Media and Unpaywall provides information about alternative Open Access locations. But there are also possibilities to add extra publications from other sources to NARCIS, for example citations from Microsoft Academic Search. also offers information about the workplace (often with an ISNI), training, grants, keywords and the like, all information that may also be used in the future to enrich NARCIS. Services such as DataCite, CrossRef and Scholix provide information about relationships between datasets and publications. In fact, a PID-Graph still offers infinite possibilities for reliably linking scientific information to each other and presenting it in NARCIS.

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