1 Ed Pentz, CrossRef The OpenURL and OpenURL Framework: Demystifying Link Resolution CrossRef, DOIs and OpenURL Ed Pentz Executive Director, CrossRef

2 Ed Pentz, CrossRef Overview What is a DOI Why CrossRef? Update on DOI developments How are DOI and OpenURL different? How do they work together? What does the future hold?

3 Ed Pentz, CrossRef Always Keep the End User in Mind Electronic journals, e-print archives and print journals together are fulfilling the needs of readers. Scientists continue to read and today choose from alternatives that satisfy their specific needs and requirements, particularly to minimize their time and effort. Carol Tenopir Collaboration and standards are critical

4 Ed Pentz, CrossRef What is a DOI? A Digital Object Identifier (DOI), is a unique string that identifies a piece of intellectual content –Prefix is assigned by a Registration Agency (CrossRef) –Suffix is assigned by publisher –DOI is a dumb number

5 Ed Pentz, CrossRef dx.doi.org taf/DynaPage.taf?file=/nature/journal/v422/n6932/full/ nature01566_fs.html DOI Directory Prefix Suffix

6 Ed Pentz, CrossRef Why DOIs are good A unique, persistent identifier but also… An actionable identifier – a resolution system with central resolution point Governance (persistence) –International DOI Foundation (IDF) – policies and standards for general DOI System; interoperability –RAs - services using the DOI System, involved in IDF governance

The DOI Community …and more !! CERN …and more !! Gateway to the DOI world Develops and maintains the DOI standard Develops and maintains the Handle system upon which the DOI executes

8 Ed Pentz, CrossRef DOI Community Growing 7 DOI Registration Agencies (including CrossRef) – scholarly publishing, e-learning, UK/EU government, scientific data sets, etc 3 national libraries joined IDF as consortium –The British Library (UK), Die Deutsche Bibliothek (Germany) and the Koninklijke Bibliotheek (The Netherlands) DTIC (Defense Technical Information Center) member of IDF German National Library of Science and Technology (TIB) – project to look at DOIs for scientific data sets The IDF is not just publishers

9 Ed Pentz, CrossRef CrossRef Mission Statement To provide services that bring the scholar to authoritative primary content, focusing on services that are best achieved through collective agreement by publishers

10 Ed Pentz, CrossRef What is CrossRef? Non-profit membership association –DOI Registration Agency for Scholarly Content Registration of metadata and unique, persistent identifiers Representation on IDF Board, TWG and RAWG –Reference linking service –Standards and Guidelines Rules governing metadata and linking Guidelines – using DOIs in journals and citations

11 Ed Pentz, CrossRef What Does CrossRef do? Makes reference linking easy and reliable for journals, conference proceedings and books Technology Infrastructure Persistent links using DOIs - no broken links in citations or database records (Average half-life of a URL is 44 days) Publishers update URLs in one location; about 50% of the records in CrossRef have already been updated Business Infrastructure –Membership agreement sets rules and creates level playing field –Business model neutral! PLOS and BioMed Central are members –no bilateral agreements needed – one agreement allows linking to over 200 publishers

12 Ed Pentz, CrossRef How CrossRef Is Used By publishers… –Deposit XML metadata for content –Parse references send to CrossRef to get DOIs –Make a reference link by sending the DOI to By secondary databases and A&Is –Links from abstract records to full text By libraries… –Submit metadata to CrossRef to get DOIs to link to full text (no cost) –Send DOI to CrossRef from local link server to lookup metadata (no cost)

13 Ed Pentz, CrossRef How CrossRef Is Used Administrative issues with libraries – more automation needed By end users… –Click on DOI links in online resources (not always aware its a DOI or CrossRef-enabled) Find DOIs using free form at CrossRef site

DOIs in Online Full Text

DOIs in Reference Citations

16 Ed Pentz, CrossRef DOIs as Article Locators

17 Ed Pentz, CrossRef DOIs in Google Reference to article Publisher Site

18 Ed Pentz, CrossRef Publish Ahead of Print

19 Ed Pentz, CrossRef Current CrossRef Stats 250 member publishers 9.1 million DOIs (5 million last year) 8500 Journals (6500 last year) –Books and conferences starting to be added 3.9 million DOI clicks in September (7- fold increase since January 02 in DOI use – this is users clicking and traffic to publishers sites)

20 Ed Pentz, CrossRef CrossRef Fees Libraries – free access since May 2003 –Interest in OpenURL integration (DOIs + metadata) –150+ libraries signed up Per DOI retrieval fee for members and secondaries will be removed starting in 2004 (revenue from annual membership fee and deposit fee) DOIs Everywhere is the goal

21 Ed Pentz, CrossRef DOIs and OpenURL DOI and OpenURL are different types of things with different purposes…but they work together DOI: unique identifier, standardized metadata, single point of resolution OpenURL protocol supports a standard way to transport metadata (which can include a DOI) The OpenURL Framework enables context sensitive linking through Local Link Resolvers OpenURL is not about unique identifiers and it doesnt provide resolution

22 Ed Pentz, CrossRef OpenURL and DOIs/CrossRef CrossRef helps solve the appropriate copy problem by providing a reverse DOI lookup (DOI in / meta-data out) id= /jmbi &pid= : CrossRef offers an OpenURL 1.0 compliant resolver : &aulast=Maas LRM &title= JOURNAL OF PHYSICAL OCEANOGRAPHY&volume=32 &issue=3 &spage=870&date=2002 (CrossRef returns DOI or will redirect to the target document) OpenURL and DOI are complementary technologies

23 Ed Pentz, CrossRef CrossRef/DOI/OpenURL Linking Two distinct modes of integration: –CrossRef/DOI localization addressing the appropriate copy problem –Article-level linking for CrossRef publishers

24 Ed Pentz, CrossRef Aggregator Local OPAC CrossRef/DOI Linking

25 Ed Pentz, CrossRef OpenURL Aware References DOI Server Server DOI OpenURL Metadata DOI link doi= /j x doi= /j x CrossRef, DOI and OpenURL

26 Ed Pentz, CrossRef Server Metadata DOI DOI link Links to Publishers

27 Ed Pentz, CrossRef Publisher Site Local Link Server Link Efficiency Publisher Site X 250 sites DOI Server

28 Ed Pentz, CrossRef

29 Ed Pentz, CrossRef Multiple Resolution Multiple URLs assigned to one DOI Metadata labels associated with URLs Relationships between DOIs captured in metadata Services associated with a DOI (mirror copies, rights clearing, ordering print) Local linking servers must be able to take advantage of DOI MR services.

30 Ed Pentz, CrossRef Multiple Resolution XML

31 Ed Pentz, CrossRef Conclusion Collaboration and standards are crucial to serving end users DOIs, CrossRef, OpenURLs and local linking servers need to interoperate In 2004 repeat the successful appropriate copy project for multiple resolution –Link resolver vendors, publishers, CrossRef, libraries all need to work together