1. DOI System: overview Norman Paskin International DOI Foundation

2. Introduction • Overview: 5 minute animation then: • More information on key points • Q and A

3. Who? • DOI = Digital Object Identifier (system) ® • International DOI Foundation (“IDF”) – Common operations and governing organisation: www.doi.org • RAs = DOI Registration Agencies – members of IDF offering the DOI system – to customers who wish to assign DOIs – to offer a DOI-based service to users

4. Status • Foundation launched to develop system in 1998. • An ISO standard: ISO 26324 • Currently used by c. 11,000 naming authorities (assigners) • e.g. 3,000 STM publishers, science data sets, entertainment industry, EU documents, etc. • 87 million DOIs assigned to date • Via 9+ RAs (international) • DOI services provided by RAs: build on DOI system • Initial applications mainly are simple redirection to a URL. • More sophisticated functionality available e.g. multiple resolution

5. Scope • Digital Identifier of an Object • Object = any entity (thing: physical, digital, or abstract) • Resources, parties, licences, etc. • Initial focus was documents/media e.g. articles, data sets. • Now also moving into parties and licences. • Extending to other sectors • Digital Identifier = network actionable identifier (“click on it and do something”) • Extensible by design: not intended as a publishing-only solution (digital convergence) • Work with existing tools and data • International: RAs worldwide.

6. DOI directory URL Content Managed DOI DOI directory DOI system DOI What it does

7. •provides a resolvable, persistent, interoperable link: •resolvable – standard identifier syntax + network resolution mechanism (Handle System) •persistent – through: –technical infrastructure (registry database, proxy support, etc) –social infrastructure (obligations by Registration Agencies) •interoperable - through a data model (semantic interoperability)

8. •International DOI Foundation •Provides common infrastructure –Technical: resolution, data model –Social: e.g. obligations for persistence, back-up, in event of failure, etc. •Deals with common issues –Standardisation, liaisons, etc. –Outreach to new communities •“Not for profit” membership federation •Registration Agencies are biggest part of membership •Elected Board, working groups, meetings •No full time staff (outsourced) Governance

9. •RAs are autonomous and independent of each other •RAs business model with their customers is decided by the RA •RAs obligation to IDF is a licence/operating agreement •All RAs share costs of common infrastructure (IDF) •All RAs implement standard DOI system •RAs can add their own services on top •RAs may choose to put DOIs “under the hood” or make a clear link •Some RAs are commercial; most are themselves member communities (e.g. CrossRef, EIDR, DataCite) RAs and the DOI business model

10. •Handle system: persistent identification in digital networks •Data model: principles for interoperability of data in e- commerce systems •Both used elsewhere: aim was to not re-invent the wheel •Handle: www.handle.net •Data Model: indecs. Linked Content Coalition Technical infrastructure

11. URL2http://a-books.com/…. XML 3 HS_ADMIN100acme.admin/jsmith XYZ 1001110011110 12 Data value DOI Data type Index 10.123/456URL1http://acme.com/…. Each DOI has one or more Handle values (type:value) Resolution can return all values, or all values of one type Schematic of a DOI Handle record PrefixSuffix Value(s) DOI uses Handle to resolve to data

12. Corporation for National Research Initiatives Bologna (2) Zurich (1) Hanover (2) Denver (1) Boston (1) Reston (2) Herndon (15) DOI Handle Servers (46 servers in 12 locations ) Singapore – Amazon Cloud (9) Beijing (1) Tokyo(1) Taipei (1) London - Rackspace Cloud (9) DOI Handle technical infrastructure

13. •High level model (from indecs) People make Content use Deals about do Data model: high level

14. Agent PlaceTime Resource Context EntityTypes An Entity may have typed relationships with Entities of any kind (including those of its own kind) EntityTypes An Entity may have typed relationships with Entities of any kind (including those of its own kind) AttributeTypes An Entity may have Attributes of any kind. (Attributes, which are a type of Resource, may have their own Attributes). AttributeTypes An Entity may have Attributes of any kind. (Attributes, which are a type of Resource, may have their own Attributes). Contextual Relationships Role Relator Descriptor Name Identifier Annotation Category Flag Quantity Attributes (illustrative: any Entity or Attribute may have Attributes of any type) Every Relationship has a Relator Verb Figure 1 COA MetaModelOverview Non Contextual Relationships (illustrative: any Type of Entity may relate to any other) Data model: in more detail

15. •Each DOI has some basic metadata –All DOIs have this “kernel” •Metadata is held and managed by the RA –Common model for DOI System •More metadata can be added –Appropriate to an RA or DOI service –Some groups of DOIs will have the same metadata terms •Extensible to any level needed •Can use existing metadata and map it to DOI •DOIs with the same service or same metadata can be grouped and managed as a class Data Model – end result

16. •Shared development – e.g. APIs, etc •Shared tools e.g. running mirror servers •Obligations for persistence: –To customers (within the RA) –In event of failure, etc.(beyond the RA) •Collaborate •Enable shared DOI services where practical –A customer could use more than one DOI service Social infrastructure

17. •ISO 26324: 2012. •Through TC46/SC9 (“Information and Documentation”) – same as ISBN etc. •ISO standard contains basic specification •DOI Handbook and procedures has more detail of implementation •Other standards: •URI (DOI via http proxy) •URN Standardisation

18. •DOI has strong focus on interoperability and on working with existing and new schemes. •Can take an existing identifier and make it a DOI: –Use the existing identifier in a DOI suffix; or –Define “same as” identifier in the DOI metadata •Enables re-use of registries, metadata, etc. •Must be certain that the existing ID and the DOI refer to the same thing (easiest in deal with an existing registry) •Complicated in digital content: –abstractions (e.g. current version or dated version; abstract work or specific edition; etc.) –Not always “same as” •Community and proprietary issues •See “Identifier Interoperability” fact sheet DOI and other identifier schemes

19. •Website: www.doi.org •Quick summary: “Key facts on DOI system” factsheet •Other Factsheets – more topics in detail: •www.doi.org/factsheets.html •DOI Handbook Documentation