UKOLN is supported by:

The Open Archives Initiative Protocol for Metadata Harvesting and ePrints UK

AULIC Institutional Repositories Meeting

University of Bristol – 23 May 2005

Andy Powell, UKOLN, University of Bath

a.powell@ukoln.ac.uk

www.bath.ac.uk

A centre of expertise in digital information management

www.ukoln.ac.uk

                                                             

2

Contents

• a brief history of OAI• 10 technical things you should know about

the OAI-PMH• potential impact…

– institutional context– the role of the library?– the researcher

• ePrints UK project

                                                             

3

OAI roots

• the roots of OAI lie in the development of eprint archives…– arXiv, CogPrints, NACA (NASA), RePEc, NDLTD, NCSTRL

• each offered Web interface for deposit of articles and for end-user searches

• difficult for end-users to work across archives without having to learn multiple different interfaces

• recognised need for single search interface to all archives– Universal Pre-print Service (UPS)

                                                             

4

Searching vs. harvesting

• two possible approaches to building a single search interface to multiple eprint archives…– cross-searching multiple archives based on protocol like

Z39.50– harvesting metadata into one or more ‘central’ services –

bulk move data to the user-interface

• digital library experience in this area indicated that cross-searching not preferred approach– distributed searching of N nodes viable, but only for small

values of N

                                                             

5

Harvesting requirements• in order that harvesting approach can work

there need to be agreements about…– transport protocols – HTTP vs. FTP vs. …– metadata formats – DC vs. MARC vs. …– quality assurance – mandatory elements,

mechanisms for naming of people, subjects, etc., handling duplicated records, best-practice

– intellectual property and usage rights – who can do what with the records

• work in this area resulted in the “Santa Fe Convention”

                                                             

6

Development of OAI-PMH• 2 year metamorphosis thru various names

– Santa Fe Convention, OAI-PMH versions 1.0, 1.1…– OAI Protocol for Metadata Harvesting 2.0

• development steered by international technical committee

• simplicity and inter-version stability helped developer confidence

• move from focus on eprints to more generic protocol– move from OAI-specific metadata schema to mandatory

support for Dublin Core

                                                             

7

Bluffer’s guide to OAI

1. OAI-PMH short for Open Archives Initiative Protocol for Metadata Harvesting

2. a low-cost mechanism for harvesting metadata records– from ‘data providers’ to ‘service providers’

3. allows ‘service provider’ to say ‘give me some or all of your metadata records’– where ‘some’ is based on date-stamps, sets,

metadata formats

4. eprint heritage but widely deployed– images, museum artefacts, learning objects, …

http://www.openarchives.org/http://www.openarchives.org/

                                                             

8

Bluffer’s guide to OAI

5. based on HTTP and XML– simple, Web-friendly, fast deployment

6. OAI-PMH is not a search protocol– but use can underpin search-based services

based on Z39.50 or SRW or SOAP or…

7. OAI-PMH typically carries metadata– content (e.g. full-text or image) made available

separately – typically at URL in metadata

8. mandates simple DC as record format– but extensible to any XML format – IEEE

LOM, ONIX, MARC, METS, MPEG-21, etc.

                                                             

9

Bluffer’s guide to OAI

9. metadata and ‘content’ often made freely available – but not a requirement– OAI-PMH can be used between closed groups– or, can make metadata available but restrict

access to content in some way

10.underlying HTTP protocol provides– access control – e.g. HTTP BASIC– compression mechanisms (for improving

performance of harvesters)– could, in theory, also provide encryption if

required

                                                             

10

Dublin Core

• OAI-PMH mandates use of simple DC as lowest common denominator

• agreed XML schema – ‘oai_dc’– simple DC – 15 metadata properties

– all DC properties optional and repeatable

Title Contributor Source

Creator Date Language

Subject Type Relation

Description Format Coverage

Publisher Identifier Rights

http://dublincore.org/http://dublincore.org/

                                                             

11

Impact on institutions…• OAI-PMH technology provides an open, relatively

stable technical framework– allows institution to re-consider management of

intellectual output– greater confidence in availability of external services

(e.g. discovery, access, analysis)

• the technical bit is easy– eprints.org software (Southampton), DSpace

(MIT/HP), Fedora

• but, technical solutions are always easy!– real problem is cultural change required to get

academics to deposit

                                                             

12

Impact on libraries…

• library is natural choice as ‘managing agent’ for the institutional repository– quality control– metadata enhancement– preservation

• but technical strengths of libraries quite variable, therefore technical collaboration within institution may be required

• beginning to see some evidence of externally ‘hosted’ repository services being offered

                                                             

13

Impact on researchers…• OAI-PMH technology provides a ‘disruptive’

technical framework that supports– new ways for individual researcher to disclose his/her

research output– development of new kinds of ‘research’ discovery

services

• can use ‘personal’ OAI repository• but, need to

– clarify roles of institutional, discipline and personal repositories

– overcome FUD – IPR, peer-review, ability to ‘publish’, quality control, inertia

                                                             

14

ePrints UK

• RDN project funded by JISC under FAIR programme

• now finished but ‘service’ still running• UK ‘service provider’• harvesting metadata from all UK eprint

archives• single point of discovery to UK eprints• working with OCLC and University of

Southampton to automatically enhance harvested metadata

http://eprints-uk.rdn.ac.uk/search/http://eprints-uk.rdn.ac.uk/search/

                                                             

15

ePrints UKeprint archive(s)

ePrints UK

OAI-PMHname

authority

subjectclassification

citationanalysis

End-user

                                                             

16

What did we learn?

• impact of eprint archives still quite low

• national coverage is potentially interesting to funders but not to end-users

• automatically enhancing metadata is difficult, particularly w.r.t.– subject classification

– name authority

• approaches to metadata creation varied – no clear cataloguing guidelines– linkage to full-text from metadata record inconsistent

                                                             

17

                                                             

18

                                                             

19

                                                             

20

                                                             

21

OAI and Google

OAI gateway

OAI gatewaymakes harvestedmetadataavailable toGoogle…

eprint archive(s)

HTTP

OAI-PMH

Examples…

DSpace and GoogleOAIster and Yahoo

                                                             

25

Questions…