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The OpenURL and OpenURL Framework:Demystifying Link Resolution
Washington DC, 29th October 2003
“Link Resolvers Explained”
Oren Beit-ArieEx Libris (USA) Inc.
The OpenURL and OpenURL Framework:Demystifying Link Resolution
Washington DC, 29th October 2003
“Link Resolvers Explained”
Oren Beit-ArieEx Libris (USA) Inc.
© Ex Libris (USA) Inc
• Open Linking framework and Context-Sensitive Link Servers
• The role of a KnowledgeBase
• Linking beyond the Full Text
• Beyond Linking …
© Ex Libris (USA) Inc
Overview
Origins of the OpenURL
The Background:• Distributed information environments • Multiple information discovery services eg A&I databases• Rapidly growing e-journal collections• Need to interlink e-collections
The Problem:• Limitations of existing linking solutions
• Information providers – not libraries – control the links• Links not sensitive to user’s context – the “appropriate copy” problem• Links dependent on vendor agreements
The REAL Problem was…
• Libraries have no (or little) say in linking
• High maintenance of proprietary solutions
• Expensive collection not used optimally
• Users not well served
Solving the Problem
The OpenURL Framework:• No hardwired links eg from a reference to the corresponding full text
• Introduction of a new component in the link process - a Link Server (OpenURL Resolver)• OpenURL – specification for interoperability between Information Resources and Link Servers
Linking I
Source
T a r g e t s
OpenURL
Link
Server
Site Specific
A p p r o p r i a t e T a r g e t s
Link to referenced
work
reference
I
Context Sensitive
The Open Linking Flow (basic)
Link Source Link Server Menu
Link Target
Menu and services under library control
Direct Link
No Menu:
Server-to-Server
(‘API’ based on OpenURL)
For the librarian: Central administration of links (and e-journal data) Local control over what types of links are offered and to where they resolve Optimizes use of licensed resources
Benefits of OpenURL linking
For the user: Desktop delivery of full text when available electronically Expands the research horizons Consistency and accuracy of links
For the information provider: OpenURL standard for outbound linking – easy to implement No need for bilateral publisher agreements More inbound links – more traffic to site! Meets need of libraries and end users
Benefits of OpenURL linking
October 2003: 10+ commercial link server solutions; other local home-grown solutions Hundreds of resources, databases and vendors actively participate in the OpenURL framework Hundreds (Thousands) of Insititutions Houndreds of thousands (Millions) of Users are being served….
The Result
What is the context in “context-sensitive” ?
1. OpenURL –
A service-request that transports information from the link source (referrer) to the user’s (requester) Link Server (resolver)
2. Resolver’s KnowledgeBase –
Defining the library’s “collection” in order to determine appropriateness of services
Two components come into play:
Entities in ContextObject/OpenURL:• Referent (the referenced resource)• Resolver (the OpenURL resolver/link server)• Referrer (the information source)• Requester (the ‘user’)• Referring Entity (eg citing Article)• ServiceType (what is requested)
ContextObject
Descriptors:
• Identfiers
• By-Value Metadata
• By-Ref Metadata
• Private Data
Encoding:
• Key/Encoded Value (KEV)
• XML
• Others…
Transports:
• HTTP(S) GET/POST
• Others (SOAP; OAI-PMH…)
Registry
NISO AX: http://library.caltech.edu/openurl
OpenURL v1.0
OpenURL v1.0OpenURL: A suite of HTTP(S)-based methods to transport
representations of ContextObjects.
Provides:• More information about the network context more means to enable context sensitive and appropriate services• Support for multiple ContextObjects (SAP-2)• Linking beyond the Scholarly Bibliographic Information domain:
- Museum objects, Learning objects, Geo-spatial objects, video/audio,…
• Linking beyond the Scholarly Information domain:
- Cities, cars, people, companies,…
Context Sensitive Linking Framework
Source
T a r g e t s
OpenURL
Link
Server
User Specific
A p p r o p r i a t e T a r g e t s
Links to referenced
works
reference
What to Link to?
And how?
Potential services
Collections Rules
OpenURL
Link Server
KnowledgeBase
Link Server – The role of the KnowledgeBase
KnowledgeBase is used to determine appropriate links to targets:
Comprehensive KnowledgeBase delivered with the Link Server
Contains a set of rules for linking to different types of targets
Library “localizes” to match local subscriptions and conditions
Requires KnowledgeBase Updates
Link Server’s KnowledgeBase
The Role of the Link Server
Augmentation of data:
Dereference Identifiers and By-Reference Metadata (OpenURL v.1.0) KnowledgeBase is used to normalize and “enhance” Metadata provided by the Link Source:
The reference might not include an ISSN, yet the Target link (eg to the Publisher) often requires it Abbreviated titles Authors names
The Role of the Link Server
http://ceres.ingentaselect.com/vl=562772/ cl=61/nw=1/rpsv/cgi-bin/cgi? body=linker& reqidx=00335533(2000)L.45
Heckman, James J. Causal Parameters and Policy Analysis in Economics: A Twentieth Century Retrospective. The Quarterly Journal of Economics, v. 115, n1 (2000): 45-97.
http://sfx.ulib.iupui.edu/sfx_local? genre=article&atitle=Causal Parameters and
Policy Analysis in Economics: A Twentieth Century Retrospective&stitle=The Quarterly Journal of Economics&date=2000&volume=115 &issue=1&spage=45&epage=97&aulast=Heckman &aufirst=James&auinit=J
OpenURL:
Link to:
• Holdings:– E-journals – OPACs– ILL/DocDel
• Extended Services– Citation Databases– Encyclopedias– Patent Databases– Search Engines– Subject Gateways– Internet bookstores– Research Tools
….. Libraries choose!
All targets must have a defined link-to syntax (which is then configured in the library’s link
server Knowledgebase)
Link Server Services
What’s missing: Targets: no link-to standard
( some adopt OpenURL as a link-to syntax)
Targets: Lacking description of collections (packages; date range; …) – missing standards ?..
Sources: good metadata
Issues
Other Needs (1)
In the beginning, most of the services provided were based on institutional affiliation (specified in the BASE_URL) More and more services and options require more granular attributes about the Requester for example:
Conditional Services (faculty; tech services; undergraduate students; …) Personalization of Services; and more …
The Requester
• Requester (User) Attributes can come through:• ‘Environment’ variables (IP-address,
cookies, certificates…)• AuthN/Z Frameworks such as
Shibboleth (Internet2/MACE project)• ContexObject’s Requester Entity (in
OpenURL v.1.0)
Other Needs (2)
• An important part of the KnowledgeBase is information about the institution’s collection:• local collection• Licensed resources• And others• Collections can be (and will be) distributed
• It is not the case that only the home Institution is responsible (licenses; creates..) for all resources that Users may have access to
We need distributed rights evaluation
CDL DoEUCDavisResources of
Information Landscape User’s Perspective
Distributed Services
UCD Link Server
merged services
CDL’s Link Server
OpenURL
OpenURL
Beyond Linking (1)
Resource for Document Delivery / ILL systems –
Query a Link Server for all electronic (and possibly also print) Holdings to facilitate docdel/ILL Especially relevant for consortia that enable direct consortia borrowing Based on a Server (DocDel/ILL) to Server (Link Resolver) query (based on OpenURL) Will make a good use of multiple ContextObjects
Central repository for ejournal subscriptions:
• OpenURL Generator
• A-Z journal title list
Utilities to export and load ejournal records (eg: full MARC) into OPAC; Portals
Research Tools:
Eg: ‘Capture Citation’ to create linkable Reading Lists (and other integrations with E-Learning Environments)
Beyond linking (2)
New challenges for Link Servers
• Use of user attributes for determination of more granular link services(Requester-entity; Shibboleth)
• Distributed KnowledgeBase and the need to determine the actual collections for any particular user, regardless of administration/licensing organizations
• More varied sources and targets – beyond linking scholarly textual information (with OpenURL v1.0)
Link Servers
Link Servers become a core component in libraries’ electronic
resources infrastructure
Oren Beit-Arie
www.exlibrisgroup.comwww.sfxit.com
Oren Beit-Arie
www.exlibrisgroup.comwww.sfxit.com
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