This post is by Matthias Liffers. He is the Product Manager for the Persistent Identifier Services at the Australian Research Data Common

Persistent Identifiers (PIDs) are a core component of a national information infrastructure and key to world-class research and innovation. In 2024, the Australian Research Data Commons released the 2024 Australian National PID Strategy – developed through a coordinated, comprehensive and collaborative process and informed by international developments and the international PID environment.

But what is a PID? It is a globally unique, unambiguous, long-lasting reference to a particular person or thing in the research ecosystem. A typical PID consists of two parts: the identifier itself, which is a unique string of characters and/or numbers; and an accompanying public metadata record.

For ease of use, most PIDs can be displayed as a URL that you can visit in your browser in order to access the metadata record. For example, the PID that refers to me (Matthias Liffers, the author of this post) is https://orcid.org/0000-0002-3639-2080. If you visit that URL, you can see a human-readable representation of the metadata record known as a landing page.

I have only one ORCID, and that ORCID will always refer to me. If another person called Matthias Liffers creates an ORCID, they will get their own. Admittedly, my name isn’t very common, but it makes more sense if you think all the researchers that are called Kim Lee or John Smith.

There are many PIDs, each suited to identifying a particular type of thing. An ORCID iD, for example, is designed for researchers and other contributors to research, whereas a DOI is more appropriate for a research output like a publication, a dataset, or a piece of research software. There are also PIDs for organisations (ROR ID) and projects (RAiD).

Why are there so many different types of PID? Because the metadata required for a human is quite different to the metadata you would need for a publication. The metadata schema for each type of PID is tailored to the type of thing you want to identify.

Generally, the person or organisation responsible for a particular thing will mint – create and assign – a PID to it. For example, a researcher would create their own ORCID and keep it through their whole career, whereas a publisher would mint DOIs for the articles in their journals. Items deposited into trustworthy repositories like Dryad, Figshare, and Zenodoreceive DOIs. If you work at a research institution, you might have access to an institutional repository that can also assign DOIs.

You might have noticed that my ORCID record contains references to my current and past employers, my education, and my publications. This demonstrates where the real power of PIDs lies – being able to make links between PIDs, so that you can establish unambiguous relationships between authors and their papers, their dataset, their affiliations, their projects, and their funding.

This global network of relationships is known as the research graph and, as more researchers and research organisations apply PIDs to their contributions to research, it gets easier to find research, establish its trustworthiness, and measure its impact on society.

To learn more about the use of PIDs in Australia, visit the Australian National PID Strategy and Roadmap website. On top of the PID Strategy, the ARDC is leading the development of RAiD – the Research Activity Identifier, as the global Registration Authority for ISO 23527:2022.

Australia isn’t the only country working on a National PID Strategy. A couple of weeks after the publication of this blog post, PIDfest 2024 will be taking place at the National Technical Library of the Czech Republic in Prague from 11-13 June 2024. It is an opportunity for PID providers like ORCID, DataCite, Crossref and the Australian Research Data Commons to come together, share knowledge, and work on pain points to make sure that when someone turns on the tap for research information, it flows.