1. DOI and CrossRef Richard O’Beirne Blackwell Publishing Seminar on Linking Technologies Edinburgh, 6 March 2001

2. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Blackwell Publishing Blackwell Publishing (2001) Blackwell Science [STM] Munksgaard [Danish STM] Blackwell Publishers [Humanities, Social sciences] Combined output 500+ journals 600 text and reference books p.a. Publishes on behalf of 550 academic and professional societies Online journals service: Synergy Also publish through 15+ aggregators and intermediaries

3. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Our involvement with CrossRef One of twelve founder members Represented on Board by John Strange Represented on Technical Working Group and System Rewrite Group by Richard O’Beirne

4. Seminar on Linking Technologies, Edinburgh, 6 March 2001 CrossRef organization Publishers International Linking Association (PILA) - independent, not-for-profit, incorporated January 2000 Board of Directors –AAAS (Science),Academic Press (Harcourt), AIP, ACM, Blackwell Science, Elsevier Science, IEEE, Kluwer, Nature, OUP, Springer, Wiley Fees, member terms, technical infrastructure and standards established See http://www.crossref.org

5. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Publisher A Publisher C Publisher D Publisher A Publisher B Publisher C Publisher D Publisher E Publisher F Publisher BPublisher E Publisher F 15 bilateral relationships6 network relationships What problem does CrossRef solve?

6. Seminar on Linking Technologies, Edinburgh, 6 March 2001 What is CrossRef? A neutral, non-profit, independent membership organization –Members: publishers of original scholarly material –Users: publishers and any organization creating links to full text articles –No need for bilateral linking agreements –CrossRef System makes broad-based linking efficient and manageable

7. Seminar on Linking Technologies, Edinburgh, 6 March 2001 CrossRef’s aims Purpose 1: Enable persistent links from primary article references to the cited articles at other publishers’ sites Purpose 2: Maximize links to full text articles from all information resources Purpose 3: Enable links between all types of scholarly content (conference proceedings, books, encyclopedias, patents, etc)

8. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Current Status 68 Member publishers (60% are non-profit) Metadata deposited for 2.7 million articles from 6100 journals 2,735,247 records in CrossRef MDDB as of Mon Mar 5 00:52:20 EST 2001 System went live in June 2000: thousands of journals with links (Elsevier, Academic Press, Wiley, Springer, Blackwell Science) 3 million+ articles in 2001 0.5-1 million new articles per year

9. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Current Status: metadata depositors Elsevier Science John Wiley & Sons, Inc. American Physical Society Academic Press The University of Chicago Press IEEE Institute of Physics Springer-Verlag AIP Blackwell Science Taylor & Francis Ltd International Union of Crystallography American Society for Biochemistry & Molecular Biol American Psychological Association OUPJOURNALS The Royal Society of Chemistry SCIENCE Nature Publishing Group PNAS Acoustical Society of America MAIK Mosby, Inc. American Vacuum Society W.B. Saunders American Mathematical Society Churchill Livingstone American Society of Plant Physiologists Munksgaard Mary Ann Liebert, Inc. Turpion Ltd. The Royal Society Geological Society of America SOR Portland Press Ltd. American Society of Civil Engineers SPIE - The International Society for Optical Engin ASME International World Scientific American Association of Physicists in Medicine American Association of Physics Teachers Biomedical Engineering Society Pion Ltd. Cold Spring Harbor Laboratory Press Electrochemical Society Lippincott Williams & Wilkins American Geophysical Union American Chemical Society NRC Research Press American College of Medical Physics Institution of Electrical Engineers

10. Seminar on Linking Technologies, Edinburgh, 6 March 2001 CrossRef System - Components Persistent Identifiers –Digital Object Identifiers (DOIs) [http://www.doi.org] Standardized Metadata –XML DTD [http://www.crossref.org] Resolution System (to get from Identifiers to Content) –DOI/Handle System [http://www.handle.net]

11. Seminar on Linking Technologies, Edinburgh, 6 March 2001 The Article Identifier Digital Object Identifier (DOI) –unique, persistent, NISO standard –DOI System routes a DOI to a URL registered by publisher (and it can do a lot more besides…) With a DOI - –linker doesn’t need to know publishers’ linking algorithms/systems –if a publisher changes their URLs (or a journal moves to another publisher), DOI-enabled links will still work –article is guaranteed to be online (only articles online get DOIs)

12. Seminar on Linking Technologies, Edinburgh, 6 March 2001 DOI resolutions since CrossRef launch

13. Seminar on Linking Technologies, Edinburgh, 6 March 2001 DOI DOI Problem –how do you know what the DOI is for an article? –CrossRef provides a database of DOIs and a DOI Lookup service (telephone book and directory assistance)

14. Seminar on Linking Technologies, Edinburgh, 6 March 2001 The CrossRef Process Publishers deposit article metadata (including DOIs) in CrossRef database Publishers query references from articles against CrossRef MDDB to lookup DOIs Publishers use DOIs to create reference links in their online journals Users click on reference links and go to other Publishers’ site

15. Seminar on Linking Technologies, Edinburgh, 6 March 2001 CrossRef Metadata Admin Stuff DOI Batch ID - uniquely identifies batch Time Stamp - uniquely identifies batch Depositor - name and email for error messages Registrant - DOI Prefix owner Content Stuff DOI - for the DOI Directory URL - where the DOI resolves Article Title (optional) Author - first author last name Publication Date - electronic/print date Enumeration (volume, issue, page) Journal Title, ISSN/Code

16. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Metadata file example

17. Seminar on Linking Technologies, Edinburgh, 6 March 2001

19. Workflow for reference linking 3. Journal production systems export articles with DOIs 2. DOI Lookup: a Journal production system requests a DOI based on citation metadata 1. Journal production systems export metadata to MDDB as new articles are published 4. Users may request and retrieve articles via DOI resolution system User CrossRef MDDB Publisher Online Journal System Publisher Production System

20. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Online Journal 1 End User DOI Directory (Handle System) Online Journal 2 1. User Gets Article 2. User Clicks DOI 3. URL Returned 4. User Gets Cited Article DOI Resolution - IDF System

21. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Business Rules/Governance CrossRef Membership –Provide full bibliographic citation for incoming DOI links (‘response page’) –many publishers will give free abstracts –information on acquiring article (pay online, document delivery, subscription) –Access to abstracts and full text controlled by publishers - business model neutral CrossRef guarantees links

22. Seminar on Linking Technologies, Edinburgh, 6 March 2001 CrossRef Fees Principles –operate on a cost recovery basis –fees should be related to system usage –no charges to end users to click links –flexibility Fees –Members: Annual Membership, Deposit, Retrieval (one-time for each DOI looked up) –Affiliates: Annual Admin Fee, Retrieval –See http://www.crossref.org

23. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Issues for the Future Multiple Resolution –one DOI = one URL is starting point –multiple locations and multiple files ‘Appropriate Copy’ Issue (a.k.a ‘Contextualization’) Prototype with libraries (DLF, CNRI, IDF) http://www.niso.org/CNRI-mtg.html Access to “Non-subscribed” Content Archive Repositories (JSTOR, ADS)

24. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Conclusion I CrossRef is a milestone –Without CrossRef broad-based linking is not feasible (high costs, business issues and technical problems) –DOIs and Metadata lay the groundwork for more sophisticated linking (URLs don’t) –CrossRef is a vehicle for publishers to work with libraries and others

25. Seminar on Linking Technologies, Edinburgh, 6 March 2001 Conclusion II Publishers need: –excellent, easy-to-use CrossRef system –technical support and information Users want: –lots of links (to content and services) –personalized/localized links –easy (not necessarily free) access to full text More work to do…

26. Seminar on Linking Technologies, Edinburgh, 6 March 2001 URLs CrossRef – http://www.crossref.org DOI – http://www.doi.org Richard O’Beirne Blackwell Publishing richard.obeirne@blacksci.co.uk