Persistent identifiers: the 7 levels of identification

1
Persistent identifiersthe 7 levels of
identification

• Juha Hakala
• Helsinki University Library
• ELAG 2005 1-3 June 2005, CERN

2
Persistence?

• Is not dependent on the identifier itself, but on
  legal, organisational and technical
  infrastructure
• ISSN would collapse without the ISSN standard, a
  community using it according to the generally
  accepted principles, ISSN International Centre
  governing the system and the ISSN database
  linking the non-semantic (that is, dumb)
  identifiers to serials
• Even a technically brilliant system may be
  discontinued if its mission breaks apart

3
Normal identifiers and resolution services

• Resolution services are a new brand of
  identifiers which render traditional identifier
  systems actionable in the Internet (Web)
  environment
• Resolve provide a link from reference to the
  resource
• Prime examples DOI and URN
• Both may encompass, at least in principle, any
  existing identifier (URN namespaces have been
  defined for e.g. ISSN and ISBN)
• Both are useless without an existing identifier
  adding flesh to the DOI/URN bones
• From now on, only normal identifiers will be
  discusses
• Complex enough topic for 35 minutes

4
Seven levels of identifiers

• After the collapse of integrated library system
  paradigm, and implementation of IR portals,
  digital asset management systems, digital
  archives, e-resource management systems, what do
  we need to identify?
• This can be analysed from top to bottom, from
  organisations to search attributes
• Such analysis may show gaps and help in design of
  identifier systems

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Top level libraries

• Identifier system must cover at least other
  (memory) organisations
• National level (union catalogue codes) exists
  due to the Internet / Web it became necessary to
  develop an international system
• ISIL, International Standard Identifier for
  Libraries and Related Organisations ISO 15511
• Consists of ISO country code, hyphen and UC code
• FI-H (Helsinki University Library)
• Danish Library Authority hosts the ISIL IC
  national centres have been established in some
  countries but the system needs wider acceptance

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2nd level collections and services

• These identifiers are important for IR portals
  international exchange of collection service
  (e.g. a Z39.50 server) metadata is cumbersome
  unless there is an efficient means for duplicate
  control
• These identifiers do not exist yet
• Helsinki University Library is writing a New Work
  Item proposal for ISO TC 46 on ISCI
  International Standard Collection Identifier
• No on-going efforts to develop service ID

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ISCI design principles

• Will be based on ISIL in order to allow efficient
  decentralization of the ISCI assignment and
  creation of Internet-wide resolution service
  without a global ISCI DB
• Will consist of three parts ISIL, delimiting
  character (colon) and the actual (colon-less)
  collection identifier
• FI-HSlavica (Slavic collection in HUL)
• Need for an international support center?

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3rd level authors

• International exchange of authority records can
  be made more efficient with persistent and unique
  identification
• ISADN, International Standard Authority Data
  Number, has been discussed for quite a few years,
  but it is not yet formally under development
• Retrospective assignment may create interesting
  ownership problems, especially if the future
  ISADN contains country of origin
• Is Franz Liszt German or Hungarian?

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4rd level identifiers for works

• ISWC International Standard Musical Work Code
• T-345246800-1
• Letter T, 9-digit unique number and check digit
• ISAN International Standard Audiovisual Number
• ISAN 006A-15FA-002B-C95F-A
• 12-digit root segment 4-digit segment for
  episode identification and check digit
• ISTC International Standard Text Code
• ISTC OA9 2005 12B4A105 6
• agency code, year, work element check digit
• These systems were developed at the same time,
  but their syntax and terminology used varies
• This should not complicate usage too much

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ISTC/ISWC/ISAN issues

• Many library system vendors are investigating the
  possibility of implementing FRBR, but few have
  been capable of doing it (VTLS, OCLC)
• Once an ILMS is frbrized, implementing work
  identifiers is essential, but there is more than
  technology to consider here
• Do we need to pay for these identifiers even
  when retrospectively generating them for old
  works?
• Who will establish the national centers and
  create the identifiers (and work level records
  they require)?

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5th level manifestations

• This used to be familiar terrain for us
• ISBN, ISSN, NBN belong here
• E-publishing has destroyed the old status quo
• Systems that worked well for decades have
  adaptation problems for different reasons
• It is not yet entirely clear if the revisions
  done (or planned) are sufficient

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E-problems with manifestations

• It is increasingly difficult to define valid
  targets
• ISSN could be assigned to any Web site out there
• Publishers want to give ISBNs to anything that
  can in principle be sold separately (e-book
  chapters, images within a book, teddy bears on
  sale in book stores)
• The number of things to be identified is growing
  fast this will cause syntax problems (ISBN
  revision was done to make more room) and staff
  issues in ISSN/ISBN national centers
• There is no point to give a persistent identifier
  to a non-persistent resource therefore resources
  must be identified, described archived which
  is labour-intensive process

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Case ISBN

• The old ISBN was running out of number space
• Several extension options were discussed
• 13, 16, even 32-digit ISBNs
• The idea to make ISBN a dumb number such as
  ISSN was voted down (for this the librarians in
  the WG are to blame)
• The new ISBN will be compliant with the EAN
  system
• 13 digits, starting with 978, 979 or in the
  future with something else to extend the scope of
  the system further
• New check digit calculation algorithm adopted
  from EAN
• It is possible to convert from an old ISBN to the
  new (starting with 978) and back
• Publishers retroconvert to new ISBNs libraries
  will keep the old ones
• ILMS need to do sophisticated things with old/new
  ISBNs

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6th level component parts

• Libraries have not done too well in this area in
  the past due to staff limitations
• We catalogue serials but not the articles
• E-publishing may force us to change tactics since
  now even component parts are separate items
  accessible directly
• Manual processing must be partially or fully be
  replaced by automated processes this will also
  have an impact on identifiers
• Automated ID generation solves the staff
  bottleneck

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SICI still alive, but not kicking

• Serial Item and Component Identifier, 1991-
• NISO standard has never really taken off
• Can be generated programmatically provided that
  the article is structured enough
• 0095-4403(199502/03)213ltgt1.0.TX2-Y
• Complex consists of ISSN and stuff identifying
  the issue and article within it
• Publishers have their own systems like PII which
  have been easier to create and maintain (for
  them)
• Still not clear how popular SICI will eventually
  be

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BICI Dead On Arrival, or conflict between theory
and practice

• Book Item and Contribution Identifier
• NISO draft standard, never completed
• Consists of ISBN and extra stuff to identify the
  relevant section within the book may be
  automatically generated
• Publishers book stores prefer to rely solely on
  ISBN in their systems
• Using ISBN only is not a neat solution (uses a
  lot of ISBNs, and giving ISBN both for the thing
  as a whole and its component parts is messy)

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7th level search attributes etc.

• Within Z39.50, sets (e.g. attribute and
  diagnostic), record syntaxes etc. are identified
  by ISO Object Identifiers
• MARC21 1.2.840.10003.5.10
• Bib-1 1.2.840.10003.3.1 term examples
• Author 1.2.840.10003.3.1.1.1003
• Name 1.2.840.10003.3.1.1.1002
• Author-name personal 1.2.840.10003.3.1.1.1004
• Personal name 1.2.840.10003.3.1.1.1

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OID problems

• Bib-1 attribute set is not quite as coherent as
  it should be, there are lots of (domestic) search
  attributes missing from it, and sometimes there
  are too many alternatives
• Attempt to develop Bib-2 failed, and even if we
  succeed in the future, co-existence of Bib-1 and
  Bib-2 may cause trouble
• ISO OIDs can be applied to anything
• Not clear how to use them in bibliographic
  context to e.g. identify government publications
  or parts of them this is currently being
  investigated in Finland

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Conclusion

• E-publishing and new applications (and their
  novel metadata) have expanded both the scope of
  identifiers needed and the requirements towards
  existing systems, especially on manifestation
  component parts levels
• Standards developers have reacted to these needs,
  but the progress has been slow still, on some
  areas system builders have been even more slow

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Conclusion (2)

• Identifier is more than just a string of
  characters
• There must be an agent which assigns the
  identifier to a resource, and (usually) describes
  it
• As long as all parts in this picture are stable,
  identification is a routine process
• Agent breakdowns have been the most common reason
  for problems in the past
• Number of national ISSN agencies are non-active
• E-resources have destroyed the balance, and it
  may take a while before the identification system
  works again in business as usual style