1. Reference Linking via CrossRef April 13, 2000 Ed Pentz Executive Director CrossRef

2. Reference Linking Next frontier in journal publishing End user access to logically related articles in one or two clicks Linking allows body of primary literature as group of logically associated articles

3. Reference Linking End Users (researchers and scientists) pursue inquiries in a logical, sequential way Researchers want everything to link Researchers expect everything to link Links Add Value

4. Why CrossRef? Current Linking –Between Secondary and Primary –Within online systems (HighWire) Linking Agreements –Bilateral - Secondary to Primary –Define terms of linking –“no surprises”

5. Why CrossRef? 1/2(N)(N-1) problem 2-party agreements not scaleable –too many publishers –too many linking schemes Result - Cooperation among publishers CrossRef makes broad-based linking manageable

6. CrossRef Goals Enable Reference Linking –initial focus on primary article to primary article links (one or two clicks) –X to primary article links important –Primary article to X links –X = A&I Databases, Local Catalogs/Holdings, Conference Proceedings, Reference Works Broad-Based, Not-for-profit initiative –All scholarly publishing

7. CrossRef Principles Aggregation (collect full text content) –duplicate/missing content/no “one stop shop” Gateway (Collect “less-than-full text”) –various models - some add value some don’t but always lead to full text content Distributed (Virtual) Aggregation ‘minimal’ centralized date - full text remains on publishers’ site access to full text determined by publisher

8. Reference Linking Infrastructure Article identifiers Resolution system Technical Infrastructure –software & services (Meta) Data Rules Business Rules

9. Article Identifier Digital Object Identifier (DOI) –just the number –unique, persistent, managed by IDF –identifies Intellectual Property, not a location (URLs) –NISO standard 10.1006/jmbi.1999.2736 http://dx.doi.org/10.1006/jmbi.1999.2736 Prefix Suffix

10. 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

11. DOI Lookup - CrossRef System DOI-X Prototype (AAP/IDF/CNRI) Reference linking prototype Metadata –Data Rules/XML DTD Metadata Database (MDDB) Reference Resolver (RR) –Academic Press/Wiley –DOI Lookup/Matching

12. Metadata Deposit Publishers submit article metadata –Journal Title, ISSN/Coden,Volume, Issue, First Page, First Author, Year - mandatory –Article Title is optional XML-based DTD (DOI-X) –Formal grammar –Supplementary “data rules” Journal articles today –Other genres to follow

13. Metadata Submission Article Metadata (XML) CrossRef Collection Service CrossRef MDDB for DOI Lookup DOI Directory DOI + URLArticle Data

14. DOI Lookup Publishers submit references to Reference Resolver (RR) –References tagged in SGML/XML –Minimum Data Abbreviated title, volume, first page - possibly first author and year –Send Batches of References –RR - intelligent “link agent”

15. Business Rules/Governance CrossRef Membership –Primary scholarly publishers –Deposit metadata/Add links to references –Provide full bibliographic citation for incoming DOI links –many publishers will give free abstracts –information on acquiring article (pay online, document delivery, subscription) CrossRef guarantees links

16. Organization Publishers International Linking Association (PILA) not-for-profit corporation to run CrossRef non-members can use system Close association with International DOI Foundation Incorporated Feb 2000 Executive Director, Board of Directors

17. Board of Directors AAAS (Science) Academic Press (Harcourt) American Institute of Physics ACM Blackwell Science Elsevier Science IEEE Kluwer Academic Nature Oxford University Press Springer Verlag John Wiley & Sons

18. Members AAAS (Science) Academic Press (Harcourt) ALPSP American Institute of Physics American Mathematical Society American Psychological Assoc ACM Blackwell Science CAB International Cambridge University Press Elsevier Science IEEE Institute of Physics Kluwer Academic Marcel Dekker Nature Oxford University Press Portland Press Royal Society of Chemistry Springer Taylor & Francis Thieme Verlag University of Chicago Press John Wiley & Sons World Scientific

19. CrossRef Fees Member Fee Annual Administrative Fee Deposit Fee Lookup Fee Principles cost recovery flexibility no charges to end users to follow links

20. Fees Primary Publisher Annual Member Fee 1 title, max 500 articles per year $200 2-5 titles, max 2,500 articles per yr $500 6-20 titles, max 10,000 articles per yr $750 21-100 titles, max 50,000 articles per yr$1,000 >100 titles or >50,000 articles per yr$2,000

21. Fees Non-Member Annual Administrative Fee Secondary, database <100,000 records/yr$2,000 Secondary, database >100,000 records/yr$5,000 Agents $5,000 Non-resellers (e.g., libraries) $300

22. Fees Deposit Fee for Primary Material Current Year -- full text$0.60 Back File (deposit after 10/1/2000)$0.10 Back File(prior to 10/1/2000)$0.05

23. Fees Member Retrieval Fee (for successful match) Current File$0.10 Back File $0.05 Non-Member Retrieval Fee (for successful match) Secondaries & Agents, Current$0.10 Secondaries & Agents, Back File$0.05 Non-reseller (libraries) $0.05

24. CrossRef and Libraries Libraries can use CrossRef system directly –submit metadata queries to get DOI –$300/year - $.05 per DOI matched Intermediaries can use CrossRef system DOIs in place when content gets to libraries Bibliographic metadata standards will streamline content syndication

25. Future Developments Multiple Resolution –one DOI = one URL is starting point –multiple locations and multiple files Appropriate Copy Issue Interoperability –Metadata is “system neutral” Collaboration - CrossRef wants to work with libraries and other parties to address these issues

26. Publisher Copy Local Copy Aggregator Copy A&I Record

27. ContactDetails www.crossref.org Ed Pentz - epentz@crossref.org