Stuart Weibel Senior Research Scientist July 1, 2005

1. DCC Workshop on Persistent IdentifiersA Layered Model Decision Making Concerning Persistent Identifiers Stuart Weibel Senior Research Scientist July 1, 2005

2. Open Univ • How do you establish that you need a persistent identifier (as opposed to a non-persistent one) • E.g. OU is creating a new course, with a very complex collection of courseware, and an equally complex workflow which manages all the parts • At what stage do we assign persistent identifiers to all the bits? • [SW:] Is this a granularity issue? • In part, but there’s ownership issues

3. CETIS • Need to be careful about advice, and who we give it to • Where’s the line between what you do and don’t need to care about • At what point does persistence become important • [PB: ‘publish’ is the crucial word here]

4. LSE • One or many systems? • Digitising a photo archive, use a separate system for that? • Who assigns identifiers at the individual school level • Managing identifier incrementation • What about managing versions in a repository? • Separate identifiers for distinct manifestations of the same article?

5. Nat Lib Scot • Anyone with experience of Nat Lib of Aus scheme?

6. Strathclyde Univ CDLR • Confession: I assign identifiers • And I’ve changed them • And changed their URLs • But, I’ve left redirects • Is this ok?

7. Edin Univ Library • How relate identifiers for a physical object to digital manifestations of that object • Preexisting vs. internal institutional identifiers • Public vs. private • How implement identifiers within a METS document • [Enders: Not a METS problem, an XML problem – SICI is not an XML ID]

8. Edin Univ Lib • If http URIs are a given, should they be opaque (e.g. ISBNs) or semantic (e.g. http://www.w3.org/REC-xml/) • “Do you know your own barcode?” • Semantic • Human readable (within a designated community, broad (native speakers of English) to narrow (well-trained biomed librarians) • vs • Rule-based, so decodable given some additional info • Opaque • E.g. ARK, random string, with (by design) no structure • E.g. LibCon(?) concatenation of year and accession number • … • What am I trading off wrt to one choice or another? • Are http: URIs intrinsically semantic?

9. Enders • If we’ve assigned identifiers, in a non-online repository, how can I get a persistent identifier? • E.g. DSPACE • [AD: DSPACE uses Handle] • [Cetis: Fedora uses Handle (?)] • [Strathclyde: Eprint.org does not offer any]

10. CETIS • Authoring and content tools should help out here • [SW: Where in workflow should identifiers be assigned?]

11. EDINA • To what extent should we have an international non-territorial view of assigning identifiers? • Or should we stay within the bounds of the nation state?

12. Glasgow Univ Lib • If from my repository I want to refer to some other repository’s identifier, in a persistent way • Can I do so responsibly independently of how they’ve done this • [JK: If they don’t publish a name they take responsibility for, don’t go there!] • Image archive example – you can email a filename and get a temporary URI (ftp:) back – how can I write down into a formal workflow a reference to “BigBear file name so-and-so” • So it’s a permanent identifier for a static digital resource, but I can’t refer to it formally • [RR: instance of general case of offline resources] • [SW: They need to be pressured to recognise the value of e.g. prepending “http:…”] • But they won’t do that today, so I’m going to do it, but that feels like breaking the rules • [??: What about names for resources in GRID computing?] • [??: One option is Handles, recently released module for Globus] • [??: Surely allocating persistent http: URIs would be overkill with 5M large images] • [SW: Publishing the naming structure is distinct from delivering all of them instantly] • [tutti: design-on-the-fly]

13. SunCat • Working on a catalogue of serials etc., heard about FRBR, etc., but inadequate for my needs, do I use the same identification scheme up and down the hierarchy • [AP: important to distinguish between application-level questions and in-principle general questions] • [PB: Application-level are not ipso facto out of scope] • And what’s an expression? • [SW: Out of scope]

14. UKOLN • Candidate functional requirements for persistent identifiers • Compare for equality • Retrieve from it • Do we get more specific, e.g. ARK? • Ding an sich [JK: or ‘suitable surrogate’] • [HST: Demurs] • Description • Cover the case where the identifier no longer identifies anything? • Change history • [PB: There’s a wealth of relevant experience] • Persistence commitment • [SW: Demur – no always desirable, sometimes not desirable] • Encode and distribute

15. NLScotland • Where would we go in ISO to do this • [PB: There is an ISO technical c’ttee…] • [RR: Wrt NISO, I can feed back on where do we go: Standards, recommendations, Best Practices notes]

16. Open Univ • Can we clarify what’s been done wrt Premis data dictionary? • Just published a new dictionary • [JK: Wrt identifiers, says nothing, judged too controversial/out of scope]

17. DCC • Is there a relationship between the identifier and the findability of a resource? • Given pervasive use of search engine • [SW, PB: What are the roles in discover and location of service]

18. British Library • If we do use http: URIs for identifiers, does the HTTP protocol provide any particular actions which make sense, e.g. PUT or POST? • Should resolution be a determiner of existence • [SW: redirection comes in here] • In theory, any 10/13 digit number can be an ISBN • What does ‘404 not found’ mean?

19. Strathclyde • Impact of search engines – people aren’t using identifiers any more • Should we question to assumption that identifiers are the entry point into access to resources

20. DCC/Hunter • What’s the impact of the fact that the community is split into two parts • Those with detailed knowledge of the identity system • Those who just have requirements which identity contributes to solving • Bookshop example • [PB: Ironmonger example]

21. Discussion candidates • Semantic vs. opaque • What should libraries do? • Is ‘retrievable’ a necessary functional requirement? • What are we identifying? • What is the connection between the identifier and the thing itself?

22. Seamus/DCC • Can we do automatic assignment of identifiers to extracts from (multiple) databases • [RR: About attaching metadata as you go] • As an author, a private person, how do I get an identifier for my work • Overwriting is OK, always? • Historical printing example feeds into thinking about multiple versions in the digital world • [PB: Relevant term is ‘provenance’ and the role of identifiers]

23. UKOLN • Are the functional requirements on identifiers across domains or classes of resources? • Conceptual • Digital • Different domains? • Physical • Work and instance… FRBR-like… Guardian… NLM persistence statements

24. EDINA • Is the distinction between persistence for ‘record’ and persistence for ‘reuse’ relevant to the design of identifiers? • Archival vs. access? • [SW: Difference in behaviour based on difference in object identified] • [Seamus: BNFL vs. BBC example]