A persistent identifier (PI or PID) is a long-lasting reference to a document, file, web page, or other object.
The term "persistent identifier" is usually used in the context of digital objects that are accessible over the Internet. Typically, such an identifier is not only persistent but actionable: you can plug it into a web browser and be taken to the identified source.
Of course, the issue of persistent identification predates the Internet. Over centuries, writers and scholars developed standards for
citation
A citation is a reference to a source. More precisely, a citation is an abbreviated alphanumeric expression embedded in the body of an intellectual work that denotes an entry in the bibliographic references section of the work for the purpose o ...
of paper-based documents so that readers could reliably and efficiently find a source that a writer mentioned in a footnote or bibliography. After the Internet started to become an important source of information in the 1990s, the issue of citation standards became important in the online world as well. Studies have shown that within a few years of being cited, a significant percentage of web addresses go "dead", a process often called
link rot
Link rot (also called link death, link breaking, or reference rot) is the phenomenon of hyperlinks tending over time to cease to point to their originally targeted file, web page, or server due to that resource being relocated to a new address ...
. Using a persistent identifier can slow or stop this process.
An important aspect of persistent identifiers is that "persistence is purely a matter of service". That means that persistent identifiers are only persistent to the degree that someone commits to resolving them for users. No identifier can be inherently persistent, however many persistent identifiers are created within institutionally administered systems with the aim to maximise longevity.
However, some regular
URLs (i.e. web addresses), maintained by the website owner, are intended to be long-lasting; these are often called
permalinks.
Examples
People and organisations:
*
Open Researcher and Contributor ID (ORCID)
*
Research Organization Registry (ROR)
Publications:
*
Virtual International Authority File (VIAF)
*
International Standard Name Identifier (ISNI)
*
International Standard Book Number
The International Standard Book Number (ISBN) is a numeric commercial book identifier that is intended to be unique. Publishers purchase or receive ISBNs from an affiliate of the International ISBN Agency.
A different ISBN is assigned to e ...
(ISBN)
Uniform Resource Identifier
A Uniform Resource Identifier (URI), formerly Universal Resource Identifier, is a unique sequence of characters that identifies an abstract or physical resource, such as resources on a webpage, mail address, phone number, books, real-world obje ...
s:
*
Archival Resource Key (ARK), with 8.2 billion ARKs issued.
*
Handle System
The Handle System is a proprietary registry assigning persistent identifiers, or ''handles'', to information resources, and for resolving "those handles into the information necessary to locate, access, and otherwise make use of the resources".
...
*
Digital Object Identifier
A digital object identifier (DOI) is a persistent identifier or handle used to uniquely identify various objects, standardized by the International Organization for Standardization (ISO). DOIs are an implementation of the Handle System; th ...
(DOI), with 200 million DOIs issued.
*
Magnet link (decentralized, with
BitTorrent
BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...
)
*
Uniform Resource Names (URNs)
*
Extensible Resource Identifiers (XRIs)
*
Persistent Uniform Resource Locators (PURLs)
*
Software Hash Identifier (SWHID)
*
Wikidata Identifier (e.g QIDs)
Combined persistent identifier and archiving functionality is provided by services such as the
Internet Archive
The Internet Archive is an American 501(c)(3) organization, non-profit organization founded in 1996 by Brewster Kahle that runs a digital library website, archive.org. It provides free access to collections of digitized media including web ...
perma.cc,
archive.today, and
WebCite such that anyone can archive a web page to prevent link rot of a URL.
References
See also
*
Authority control
External links
*Juha Hakala
"Persistent identifiers – an overview."Posted to Technology Watch Report (TWR): Standards in Metadata and Interoperability, 13 Oct 2010.
*Hans-Werner Hilse and Jochen Kothe,