DLF Forum Presentation on EZID, Persistent Identifier Service

1. EZID: Easy Persistent Identifiers
and Data Citation
31 October 2011
John Kunze and Joan Starr
California Digital Library

2. EZID:
Easy Persistent Identifiers & Data Citation
Introduction
Citation, DataCite and EZID
Who? Why? What?
EZID’s next steps: tech talk
New stuff, use cases, feedback
Feedback

3. California Digital Library (CDL)

5. The research data problem
an article about data, but no data

6. What citation offers
• To aid scientific reproducibility
• To provide fair credit
• To ensure scientific transparency and
reasonable accountability
• To aid in tracking the impact, including
– helping data authors verify use of their data and
– helping future data users identify how others have
used the data

8. DataCite
German National Library of Economics (ZBW) Canada Institute for Scientific and Technical Information
German National Library of Science and Technology (TIB) (CISTI)
German National Library of Medicine (ZB MED) Technical Information Center of Denmark
GESIS - Leibniz Institute for the Social Sciences, Germany Institute for Scientific & Technical Information (INIST-
Australian National Data Service (ANDS) CNRS), France
ETH Zurich, Switzerland TU Delft Library, The Netherlands
The Swedish National Data Service (SNDS)
The British Library , UK
California Digital Library (CDL), USA
Office of Scientific & Technical Information (OSTI), USA
Purdue University Library

9. EZID: long-term identifiers made easy
take control of the
management and
distribution of your research,
share and get credit for it,
and build your reputation
through its collection and
documentation
Primary Functions
1. Create persistent identifiers
2. Manage identifiers over time
3. Manage associated metadata over time

10. http://n2t.net/ezid

11. Current EZID Clients
A partial list
UC Berkeley Library (on behalf of the UC Berkeley The Digital Archaeological Record (tDAR)
campus) Sponsored accounts:
Open Context Dryad Digital Repository
CRCNS.org
UC San Diego Library (on behalf of the UC San Diego Fred Hutchinson Cancer Research Center
campus)
American Astronomical Society (AAS) LabArchives
Centre national de documentation National Center for Atmospheric Research
(NCAR)
pédagogique (CNDP)
Cornell Institute for Social & Economic USGS/Earth Sciences Data Clearinghouse
Research (formerly National Biological Info. Infrastructure)

12. New features in trial or active development
• Service replicas: manager and resolver
• URN (Uniform Resource Name) support (urn:uuid:)
• Suffix pass-thru: do NT and get N/ST/S for free
• Tombstone/incubation/... surrogate pages, id
status (reserved or public), and multiple targets
• Identifier status: reserved or public
• Content negotiation and inflections: ? ?? / .
• ARK community and governance, eg, registries

13. Service replicas
• EZID is an id manager that populates N2T
– It tolerates down time
– Other id manager services might one day populate N2T
• N2T (Name-to-Thing) is an id resolver that ...
– It is very intolerant of down time, since it services all
access requests for locations and metadata
– N2T was designed with global replication in mind

14. URN support
• N2T and EZID are agnostic about kinds of things,
names, and metadata
– Digital, physical, abstract, living, fictional, groups, etc.
– Any metadata & known profiles (DataCite, Dublin Kernel)
– ARK, DOI, URN, Handle, IVOA, LSID, PMID, etc., requiring
namespace “write” permission, eg, via DataCite
• In test: Uniform Resource Names (URNs)
– urn:uuid namespace

15. Under the hood keysmithing terms:
bows, shoulders, blades, tips, covers

16. Suffix pass-thru: NT gets N/ST/S for free
Idea: if name N points to target T, then requests for N
extended by any suffix N/S can take you to T/S
• For dataset doi:10.5072/Big4 with 10,000
nameable components,
– Register and manage 10,001 names or 1 name?
– Eg, http://x.y.z/foo/Big4/db/table/cell/45-8.txt could be
reached with doi:1.5072/Big4/table/cell/45-8.txt
• In test with ARKs. Conflict with other resolvers?

17. Tombstone and other surrogate pages
Tombstone, incubation, and other surrogate pages
(probation?) auto-generated from metadata, eg,
http://n2t.net/ezid/tombstone/id/ark:/20775/bb3243444z

18. Reserved identifiers and multiple targets
• Some ids must be created and managed (reserved)
before going public, eg, for manuscript preparation
• In test: infrastructure for multiple targets and
multiple instances of any metadata element
• What should user experience be for multiple targets?
– Present a menu of targets (burden of choice)?
– One target chosen for them (burden of inflexibility)?

19. Identifier (ARK) inflections: ? ?? / .
• Inflect: change endings w.o. creating new words
– Terminal ? means “I want metadata”, which is similar to
linked data content negotiation (also in EZID test)
– Terminal ?? means “I also want support metadata”
– Drawing board: / could mean “I want a landing page”
and . could mean “I want the usual computable thing”
• Allow inflections beyond ARKs to DOIs/URNs?

20. Example: http://n2t.net/ark:/13030/qt0349g1rh?
Renninger, Heidi; Phillips, Nathan; Hodel, Donald. “Comparative hydraulic and
anatomic properties in palm trees (Washingtonia robusta) of varying
heights”. 2009-04-29. ark:/13030/qt0349g1rh
HTML content with
embedded comments in
ANVL/ERC and RDF
erc:
who: Renninger, Heidi,; Phillips,
Nathan,; Hodel, Donald,
what: Comparative hydraulic and
anatomic properties in palm
trees (Washingtonia robusta)
of varying heights
when: 2009-04-29
where: ark:/13030/qt0349g1rh

21. ARK community and governance
• ARKs soon to have a mailing list
• Topics: governance, community, standardization
• Registry maintenance: shoulders and NAANs
• N2T consortium with alternative EZID-like services

22. For information
• http://www.cdlib.org/services/uc3/ezid
• Understanding ids and conventions (shoulders, etc)
• Choosing the right identifier (ARK vs DOI? ARK and DOI?)
• EZID FAQs and N2T vision
• EZID Service Guidelines
• EZID Handout/brochure
• EZID webinars & slides
Contact Joan Starr at uc3@ucop.edu

23. For (even) more information
EZID
http://n2t.net/ezid/
http://www.cdlib.org/services/uc3/ezid/
UC Curation Center
http://www.cdlib.org/uc3
uc3@ucop.edu
UC3 webinar series
http://www.cdlib.org/uc3/uc3webinars.html
UC3/CDL
Stephen Abrams David Loy
Lisa Colvin Mark Reyes
Patricia Cruse Abhishek Salve
Scott Fisher Tracy Seneca
Erik Hetzner Carly Strasser
Greg Janée Joan Starr
John Kunze Marisa Strong
Margaret Low Perry Willett

24. Questions?
by Horia Varlan
http://www.flickr.com/photos/horiavarlan/4273168957/in/photostream/