Connected Research: The Potential of the PID Graph

Persistent identifiers (PIDs) provide unique and long-lasting references to entities. They enable uniqueidentification persistently over time and hence play a crucial role in supporting the FAIR (Findable, Acces-sible, Interoperable, Reusable) principles. In this paper, we describe how the benefits of PIDs can beamplified by connecting them via their metadata. We are introducing the next step in PID infrastructure:the PID Graph. The PID Graph establishes connections between different entities within the research land-scape, thereby enabling both researchers and institutions to access new information. The paper closeswith three recommendations, which will help to optimize the use and value of PIDs within the researchecosystem. INTRODUCTION The need for sharing research findings and integrating existinginformation to facilitate new discoveries is more evident thanever. With major steps being taken toward the implementationof transcontinental infrastructures such as the European OpenScience Cloud (EOSC), AmeliCA, and several national infrastruc-tures to share research outputs, it is timely to examine the use ofidentifiers and metadata in connecting research. Taking the EOSC as an example, Persistent identifiers (PIDs) are a promi-nent component of the European scientific ecosystem, 1 and a PID policy for the EOSC has been formulated. 2 To enhance the value of research, resources should be made FAIR (Findable, Accessible, Interoperable, and Reusable). 3 To enable a FAIR research landscape, a technical infrastructure is needed that allows digital information to be found and accessed in a reliable and sustainable manner. 4 PIDs are a crucial aspectof this technical infrastructure, playing a role in each of theFAIR elements. 5A PID is a uniqueand long-lasting reference to anentity, such as a dataset, paper,or person. It is amachine-readable string of char-acters, which conforms to a defined lexical scheme and must be associated with one, and only one, entity within the world. 6 Unlike a uniform resource locator (URL), a PID reliably points to that. THE BIGGER PICTURE PIDs provide unique and long-lasting references to entities and play a crucial role in research infrastructure. They enable unique identification persistently over time and contribute to making research entities more FAIR (Findable, Accessible, Interoperable, and Reusable). The benefits of PIDs can be amplified by connecting them via their metadata. Therefore, we are introducing the next step in PID infrastructure: the PID Graph. The PID Graph establishes connections between different entities within the research landscape, thereby enabling researchers and institutions to access new information. Through the PID Graph, the infrastructure is in place to answer new questions about connections within theresearch world. However, these will only have meaningful answers if sufficient information is present within the PID Graph. Therefore, the paper closes with three recommendations for different stakeholders, which will help to optimize the use and value of PIDs within the research ecosystem