Information Technology Reference
In-Depth Information
Persistent identifiers (PIs) attempt to solve the problems of location-
based identifiers such as the uniform resource locator (URL), which can
often lead to problems in accessing resources, caused by the resource
being moved, relocated or renamed while external links to the resource
remain unchanged. PIs give the resource a unique identifier that will
not change over time, allowing for reliable referencing and access.
Emma Tonkin (2008) identifies a number of standards 'at a mature
stage in development':
the Uniform Resource Name (URN)
the persistent URL (PURL); the Handle system
the digital object identifier (DOI)
National Bibliography numbers (NBNs)
the Archival Resource Key (ARK)
the OpenURL.
The JISC Standards Catalogue
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gives a detailed explanation of these
standards, including those listed above and many others. For the
purposes of resource discovery, this chapter will concentrate on the DOI
and the OpenURL.
Digital Object Identifier (DOI)
The DOI System was developed as a cross-industry, cross-sector, not-for-
profit effort managed by an open membership collaborative development
body, the International DOI Foundation (IDF) founded in 1998.
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The DOI could be described as the telephone number of a journal
article; however, like any telephone number, it needs a directory in
order to be discovered. In the case of scholarly content, this directory
service is provided by CrossRef, the official DOI link registration agency
for scholarly and professional publications. Each record in the CrossRef
database consists of a triplet: {metadata + URL + DOI} in order to
facilitate resource discovery.
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Since the foundation of CrossRef, over 2800 publishers have
participated, adding over 20,000 journals and e-books. This resource
has proved crucial to resource discovery, in that citations listed in
