1. DOI Workshop, Luxembourg - 20 May 1998 1 Identifiers in Context Andy Powell UKOLN University of Bath a.powell@ukoln.ac.uk http://www.ukoln.ac.uk/ UKOLN is funded by the British Library Research and Innovation Centre, the Joint Information Systems Committee of the Higher Education Funding Councils, as well as by project funding from the JISC’s Electronic Libraries Programme and the European Union. UKOLN also receives support from the University of Bath where it is based.

2. DOI Workshop, Luxembourg - 20 May 1998 2 Overview Issues? Functional requirements for identifiers Around the identifier landscape in 15 minutes! Traditional identifiers Identification on the Internet How does the DOI fit into this? Conclusions

3. DOI Workshop, Luxembourg - 20 May 1998 3 Issues Usage resource discovery discover, locate, request, deliver commerce - rights management citation in-house resource management What do we want to identify work - version - manifestation whole - part digital - physical

4. DOI Workshop, Luxembourg - 20 May 1998 4 Issues (2) Dumb or intelligent identifiers can the identifier be derived from the resource? Resolution resource, metadata, order form Persistence what happens when resource ceases to exist or is no longer commercially available?

5. DOI Workshop, Luxembourg - 20 May 1998 5 Functional requirements Global scope Globally unique Persistent Scalable

6. DOI Workshop, Luxembourg - 20 May 1998 6 Books and journals... ISBN International Standard Book Number Paperback/hardback can have different ISBNs ISBN 0-7475-2266-9 ISSN International Standard Serial Number ISSN 1361-3200

7. DOI Workshop, Luxembourg - 20 May 1998 7 …parts of books and journals SICI Serial Item and Contribution Identifier Serials, parts of serials… and fragments NISO standard (1991 and 1996) Submitted to ISO Widely used Incorporates ISSN 0730-9295(199206)11:2 2.0.TX;2-X

8. DOI Workshop, Luxembourg - 20 May 1998 8 …parts of books and journals PII Publisher Item Identifier Scientific and Technical Information (STI) group of publishers (1995) S0165-3806(96)00403-8 BICI Book Item and Component Identifier Uses ISBN Proposed NISO Z39 standard Books, chapters and excerpts

9. DOI Workshop, Luxembourg - 20 May 1998 9 Other communities... ISWC International Standard Work Code Music industry - based on ISMN Part of CIS, submitted to ISO SMPTE Society for Motion Picture and TV Engineers National Bibliographic Agencies National Bibliography Number (NBN)

10. DOI Workshop, Luxembourg - 20 May 1998 10 Internet - URL Uniform Resource Locator Locator - not true identifier! Access protocol, site, filename http://www.ukoln.ac.uk/metadata/report.html Consider... gopher://gopher.bath.ac.uk/00/prospectus/ http://www.bath.ac.uk/Prospectus/ Can support some movement of resource using HTTP redirects

11. DOI Workshop, Luxembourg - 20 May 1998 11 HTTP Redirects HTTP redirect http://www.host1.com/something/ Web server http://www.host2.com/otherthing/ Web server

12. DOI Workshop, Luxembourg - 20 May 1998 12 Internet - PURL Persistent URL OCLC Interim solution Database of PURL/URL mappings PURL database HTTP redirect Resource http://purl.org/metadata/dublin_core purl.org Web server

13. DOI Workshop, Luxembourg - 20 May 1998 13 Internet - URN Uniform Resource Name IETF Working Group Work in progress... Syntax - RFC URNs based on existing identifiers Resolution protocol HTTP and DNS Support in browsers required urn:issn:1361-3200 urn:isbn:1-56592-262-X

14. DOI Workshop, Luxembourg - 20 May 1998 14 The DOI Digital Object Identifier Proposed by AAP, governed by IDF 10.1000/7 Based on Handle system Currently resolved using HTTP http://dx.doi.org/10.1000/7 Distributed Handle database HTTP redirect Resource dx.doi.org Web server

15. DOI Workshop, Luxembourg - 20 May 1998 15 Where does the DOI fit in? The DOI as URN? urn:doi:10.1000/7 Other identifiers in DOIs 10.1234/[ISBN]1-56592-262-X 10.3456/[SICI]0730-9295(199206)11:2 2.0.TX;2-X

16. DOI Workshop, Luxembourg - 20 May 1998 16 Identifier questions... Scope? What? Assignment rules? Who, when? Derivability? How is identifier determined? Resolution? Who? Policies? Persistence? How long? Resource availability? …proposed by Clifford Lynch, CNI