1. CrossRef Linking and Library Users “The vast majority of scholarly journals are now online, and there have been a number of studies of what features scholars find most valuable in e-journals. Seamless linking to and from citations, the original articles cited, and bibliographic databases always ranks extremely highly. DOI and CrossRef provide an increasingly flexible way of enriching scholarly literature online with actionable and persistent links.” -- Sally Morris, Chief Executive of the Association of Learned and Professional Society Publishers

2. Outline • Why the DOI and CrossRef? • What’s a DOI? • What does CrossRef do? • DOIs in Use • How CrossRef Enhances OpenURL Linking • CrossRef’s Benefits to Librares and Users

3. The use of Internet references in academic literature is common, and Internet references are frequently inaccessible. The extent of Internet referencing and Internet reference activity in medical or scientific publications was systematically examined in more than 1000 articles published between 2000 and 2003 in the New England Journal of Medicine, The Journal of the American Medical Association, and Science. Internet references accounted for 2.6% of all references (672/25548) and in articles 27 months old, 13% of Internet references were inactive. Publishers, librarians, and readers need to reassess policies, archiving systems, and other resources for addressing Internet reference attrition to prevent further information loss. Dellavalle et al., INFORMATION SCIENCE: Going, Going, Gone: Lost Internet References, Science 2003 302: 787-788 (DOI:10.1126/science.1088234) Why the DOI and CrossRef?

4. What’s a DOI? • Analogous to the UPC bar code for physical objects, a digital object identifier is an alphanumeric string created both to: • uniquely identify/name a piece of electronic content, and to • serve as a stable, persistent link to that content’s location on the web

5. DOI: THE persistent identifier • DOI is the only widely adopted persistent, actionable identifier for online scholarly works • A DOI persists throughout changes in copyright ownership or location because it’s just a name used to look up an address in an easily updateable directory • The core functionality of the DOI system is to resolve the DOI to the registered, updateable URL

6. What’s a DOI look like? The DOI syntax is a NISO standard In future, internet browsers will handle DOI s natively

7. CrossRef’s mission • To provide services that bring the scholar to authoritative primary content, focusing on methods that are best achieved through collective agreement by publishers

8. What Does CrossRef Do? • Provides technology infrastructure for linking No broken links in citations or database records because it uses the DOI • Provides business infrastructure for linking One agreement with CrossRef is a linking agreement with all CrossRef publishers

9. Handle System CrossRef/DOI linking recap DOI Resolver dx.doi.org Repository Cited Item DOI 10.1000/123 Citation with DOI link CLICK 10.1000/123 http://abc.publisher/page2 Full text

10. DOIs in Print

11. DOIs in Table of Contents

12. DOIs in Online Full Text

13. E-First Publishing

14. DOIs in Reference Citations

15. DOIs in PubMed DOI link No DOI shown

16. DOIs in Google Reference to article Publisher Site

17. DOI links on the rise!

18. DOI and OpenURL • OpenURL is not an alternative to CrossRef and DOIs – they work together • The DOI system and CrossRef are OpenURL aware; therefore publishers are OpenURL enabled via use of CrossRef and DOIs

19. Appropriate copy problem Aggregator Local OPAC

20. Localized linking via DOI redirection • Library installs local linking server • User in library context clicks on a DOI link • A “cookie” on user’s machine alerts DOI proxy server to redirect this DOI to the local linking server • Article-level metadata needed for local resolution can come from the source of the link or from CrossRef via OpenURL

21. CrossRef, libraries, & the OpenURL • CrossRef members are automatically OpenURL-enabled by via DOI redirection • The DOI and OpenURL are complementary technologies • CrossRef integrates with several local linking solutions • CrossRef access is free for libraries!

22. OpenURL Aware OpenURL Linking Complements CrossRef References DOI Server Server DOI OpenURL Metadata DOI link http://www.sfx.edu/? doi=10.1034/j.1399-0039.2000.560502.x http://dx.doi.org/ doi=10.1034/j.1399-0039.2000.560502.x

23. CrossRef Benefits Libraries and Users • User navigation at the article level leads to increased usage of electronic resources (access) • DOI links can extend access to content not owned (access) • CrossRef provides persistent DOI links (valid and robust) • CrossRef helps find the appropriate copy (appropriate and in context) • Article-level metadata look-up makes CrossRef publishers OpenURL compliant Every month, over 5 million DOIs get clicked…

24. …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 The DOI Community

25. DOI is the persistent linking standard. The CrossRef network is rapidly expanding and already includes hundreds of primary and secondary publishers, hundreds of libraries, and millions of links….