Use Cases for Persistent Identifiers Charles Duncan Intrallect Ltd C.Duncan@intrallect.com

Use Cases for Persistent Identifiers

Charles DuncanIntrallect Ltd

C.Duncan@intrallect.com

Confession

• I don’t know much about identifiers• I do know what I could do with them• Two communities

– Those who want to define the functional specifications of persistent identifiers and their resolvers

– Those who don’t care about that, but want to do things that are only possible if identifiers work in the background

Persistent Identifiers

• Why?– Benefits

• To the owner • To others

• How?– Technologies– Processes

Imagine…

• You have just been asked to create a new medical course (Brain Surgery 101)

• A colleague in another university passes you the identifier of a reading list she has used

• You locate the list and find a useful learning object• You use a web service to find the most current version of the

learning object• You use another web service to search for every course in

which that learning object is used• You use another web service to locate secondary metadata

(reviews, comments, annotations, usage statistics) for the object and the courses

• You use another web service to differentiate the right (terms and conditions of use) of the courses and all their components

• You build a course based on high-quality, well-used, elements of different courses which are free and whose use is not time-limited, adding your own material

• You make your own course available

Previous work

• ERPANet: Persistent identifiers– Electronic Resource Preservation and Access

Network– Cork, 17-18th June 2004– Surveyed identifiers and their users

• CETIS: Learning object identifiers– Centre for Educational Technology

Interoperability Standards– London, 21 Oct 2003– Surveyed uses for identifiers

ERPANet CETIS

• Publishers• Archives• Libraries• Repositories

• Mechanisms• Persistence• Resolvability• Tools

• E-learning• Self-publishing• Repositories• Federations of

repositories

• Uses• Format• Actionability• Persistence

Identifiers needed for

• Digital material– E-publications– Learning objects– Media object– Data – Metadata

• Non-digital material– Books – Journals– People– Organisations– Locations– Events

Stakeholders

• Libraries• Publishers• Archives• Repositories• Object creators• Object users

Just do it

• A system needs identifiers, choose one, and make it work

• A community needs identifiers– Many independent decisions-makers– Many proprietary and non-proprietary

systems– Some degree of local autonomy needed– How are decisions reached– How are processes standardised

• Lessons from ISBN?

CETIS Metadata SIG list

• “Do I need identifiers for both objects and metadata in my repository”

• “It depends on what you want to use them for”

• “You shouldn’t need to worry too much, appropriate identifiers should be generated automatically by your repository”

Focus on learning objects

• Is a learning object complicated?– Granularity– Versions– Relating metadata to entities– Relating entities to entities– Dynamic entities

• Complications similar to scientific data

Create and Deposit

Metadata

REPOSITORY Z

rdn.ac.uk

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifierrdn.ac.uk/z-meta-1234

New version

Metadata

REPOSITORY Z

Metadata

Metadata

Entity-identifierrdn.ac.uk/z-62847

Metadata-identifierrdn.ac.uk/z-meta-1367

Relation-identifierisVersionOf

rdn.ac.uk/z-67890

rdn.ac.uk

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifierrdn.ac.uk/z-meta-1234

Relation-identifierhasVersion

rdn.ac.uk/z-62847

Duplicate in another repository

REPOSITORY Z

Metadata

rdn.ac.uk

Metadata

REPOSITORY X

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifier

bath.ac.uk/z-meta-set23

bath.ac.uk

New entry in metadata catalogue

REPOSITORY Z

Metadata

Metadata

CATALOGUE A

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifier

ltsn.ac.uk/217461 rdn.ac.uk

ltsn.ac.uk

Aggregate and store

REPOSITORY Z

rdn.ac.uk

Metadata

Metadata

REPOSITORY V

MetadataMetadata

MetadataMetadata

Metadata

gla.ac.uk

Metadata

Entity-identifiergla.ac.uk/ab.123.x

Metadata-identifiergla.ac.uk/cf.657.m

Relation-identifierhaspart

rdn.ac.uk/z-67890

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifiergla.ac.uk/ce.311.m

Relation-identifierispartof

gla.ac.uk/ab.123.x

Move aggregation - disaggregate

rdn.ac.uk

REPOSITORY Z

Metadata

Metadata

REPOSITORY V

Metadata

Metadata

Entity-identifiergla.ac.uk/ab.123.x

Metadata-identifierrdn.ac.uk/z-meta-3999

Relation-identifierhaspart

rdn.ac.uk/z-67890 gla.ac.uk

Multiple metadata for one LO

REPOSITORY Z

Metadata

rdn.ac.uk

Grant Cocks, Simulacra

Metadata

CATALOGUE A

Metadata

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifierltsn.ac.uk/890

ltsn.ac.uk

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifierltsn.ac.uk/891

Multiple resolutions in one LO

Metadata

REPOSITORY Z

rdn.ac.uk

Metadata

Entity-identifierrdn.ac.uk/z-67890

Metadata-identifierrdn.ac.uk/z-meta-1234

locationresolution-low.avi

resolution-medium.aviresolution-high.avi

Gayle Calverley, U of Manchester

Metadata

Metadata

Metadata

REPOSITORY Z

ed.ac.uk

Metadata harvesting

Phil Barker, CETIS

REPOSITORY Z

rdn.ac.uk

Metadata

Metadata

Metadata

The HUB

ltsn.ac.uk

Metadata

REPOSITORY X

bath.ac.uk

Metadata

Metadata

Metadata

Metadata

Metadata

Metadata

Metadata

MetadataMetadata

Metadata

Metadata

Metadata

Metadata

Metadata

MetadataOAI-PMH

Some duplicate objectsbut not duplicate metadatarecords – different descriptions

Multilingual, multibrand, multiversion

Metadata

Metadata

Metadata

REPOSITORY Z

c.com

REPOSITORY Z

b.com

Metadata

Metadata

Metadata

Metadata

REPOSITORY X

a.com

Metadata

Metadata

Metadata

Metadata

Metadata

Metadata

Metadata

MetadataMetadata

Metadata

Metadata

Metadata

Metadata

Metadata

Metadata

Dan Rehak, Carnegie-Mellon

Metadata

PreferencesSearches based on:Object identifierBrand styleLangauge (LIP)

BrandStyle

Issues

• Don’t define the solution until you have defined the problem

• Defining processes for using identifiers is as/more important than choosing identifiers

• Many, diverse “publishers”• Cost/effort at point of issue• What needs an identifier (ephemeral –

permanent)?• Properties of identifiers (Uniqueness, Persistence,

Action)• Automatically generated when needed• Services built on use of identifiers• Does it matter which identifier?

OpenURL