Introduction to Linking Technologies

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Introduction to Linking Technologies OpenURL

• Lori Jean Ostapowicz Critz
• Georgia Institute of Technology
• 5/20/04

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Linking Technology

• Permits context-sensitive linking between various
  web-based resources
• Allows libraries to combine electronic resources
  (full-text journals, abstracting indexing
  databases, citation databases, online library
  catalogs, interlibrary loan/document delivery
  systems, search engines) to function as a
  cohesive, one-stop reference system

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OpenURL Framework

• Provides a means of DESCRIBING a reference
  resource along with a description of the CONTEXT
  of the reference
• Also defines methods of TRANSPORTING these
  descriptions between networked systems
• Used to REQUEST SERVICES pertaining to the
  referenced resources that are appropriate for the
  requestor (i.e. enables context-sensitive linking
  from a reference in a scholarly system to
  resources relevant to the reference)

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OpenURL Framework

• A user clicks a link or a button in an HTML page
  (usually in an abstracting indexing database or
  in a reference list of an electronic journal
  article)
• As a result of activating the link or button, a
  description of the scholarly resource (such as a
  journal article) is transported (e.g. via
  HTTP(S) GET or POST) to a LINKING SERVER along
  with information about the dynamic context of the
  reference
• This dynamic context enables a list of relevant
  services, appropriate to the user, to be provided
  
• The LINKING SERVER and its RESOLVER SOFTWARE
  processes the description/information to provide
  this list of options/services (full-text print
  holdings interlibrary loan, )

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How Does the System Work?
Begins with SOURCES that can send an OpenURL to
the Linking System/server (Where the user begins
the search!)
A I Databases
OPAC
Publisher sites
Aggregated Databases
OpenURL
OpenURL
OpenURL
OpenURL
The System evaluates the request and looks for
options that can be provided for the desired item.
OpenURL-enabled Library Linking System
Subscription Agents
Aggregated Databases
PUBLISHER SITES
Ends at TARGETS that lead to the desired item or
presents alternatives for finding it. (Where the
user lands!)
OPAC
INTERLIBRARY LOAN
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Link resolvers manage the linking process
ISI
Ingenta
Publisher sites
The Resolver can link to the resources.
Information sources need only to know how to link
to a link resolver. Resolver is usually
controlled by the library. The Resolver is the
one place that manages holdings and links.
Link Resolver
Full text DBs
More Publisher sites
Library
AI service
Google
Adapted from Oliver Pesch Chief Architect, EBSCO
Publishing
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Without a link resolver the user may notaccess
the appropriate (i.e. free full-text) copy
ISI
Pay per view
Ingenta
A
Publisher sites
Full text DBs
Other Publisher site
Library subscribes
A
With a predefined link, the user may be presented
with a link and not have a choice where that link
goes
Library
AI service
Google
User
Adapted from Oliver Pesch Chief Architect, EBSCO
Publishing
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With a link resolver, the library candetermine
which copy is appropriate
ISI
Pay per view
Ingenta
A
Publisher sites
?
Link Resolver
Full text DBs
Other Publisher sites
Library subscribes
A
With the resolver, the library can control where
the link goes and get the user to the appropriate
copy. As long as the AI service knows the
user/library has a resolver and where it is, it
can create the link.
Library
AI service
Google
User
Adapted from Oliver Pesch Chief Architect, EBSCO
Publishing
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Components of Linking System

• OpenURL- enabled Content Providers
• Called SOURCES or REFERRANTS or REFERRING SOURCES
• Generate the OpenURL to start the process
• Can also serve as targets (e.g. Proquest) if
  linked TO by link resolver/server
• Data about the Collection
• Inaccurate data leads to linking errors,
  incomplete holdings information, and inaccurate
  availability statements
• Resolver
• Performs the comparison between the collection
  /holdings and the desired cited item
• Displays options/results (e.g. links to full-text
  or OPAC) and additional features (e.g. links to
  ILL/document delivery, Google search, Endnote
  connection)

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Linking Technology in Action
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A search in CSA Sociological Abstracts (the
SOURCE) leads a user to a citation for a desired
item
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The citation is described, in part, by the
following metadata Article Title Cultural
Values and Happiness An East-West Dialogue
Journal Journal of Social Psychology ISSN
0022-4545 Author Lu, Luo Gilmour, Robin Kao,
Shu-Fang Start Page 477 Volume
141 Issue4 Date Aug. 2001
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When the user clicks on the link resolver logo or
link (SFX in this case), the OpenURL carries the
metadata about the article to the link resolver.
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The OpenURL that describes the citation would
look something like this http//VD2YN4ULBU.linkr
esolver.com/?atitleCulturalValuesandHappiness
3AAnEast-WestDialoguevolume141issue4date
2001spage477aulastLuaufirstLuoissn0022-454
5titleTheJournalofsocialpsychology The
OpenURL organizes the metadata
The domain section (BASEURL) of the URL points to
the Link Resolver/server (e.g. SFX) that will
process the OpenURL. Typically, each library has
one link resolver to which all their OpenURLs
point.
The QUERY section contains the metadata and
values for the citation.
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Description/Context Object
Description of the referenced item and the
context of the referencing action
Version control, character encodings, timestamp,
etc.
Administrative
Referent
Item being referenced. (e.g. bibliographic
reference in full text article)
User making the request
Requester
Service creating the link. (e.g. where the user
found the reference)
Referrer
ReferringEntity
The item which contains the reference. (e.g. the
article in which the bibliographic reference was
found)
Resolver
ServiceType
The target of the link - the link server of the
users institution
The desired services from the Resolver. ( Full
text, ILL, Abstract, etc.)
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The Link Resolver compares the data about the
item described in the OpenURL with data
(knowledge base) about what is held/owned/accessib
le in the librarys collection The Link Resolver
determines if the user has access to this article
---- and, if so, what links it should create for
the user.
INFORMATION SOURCE
OpenURL
Resolver
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The Link Resolver then displays the
options/services available to the user (based on
the metadata encoded in the OpenURL).
SFX Menu of 'options'
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The user then selects the best option (full-text,
link to print holdings record, ILL ) and is
presented that option.
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Full Text
The options that can be provided vary with the
resolver systems used and are quite diverse!
Union Catalog Search
Document Delivery
Record Downloads
Web Search
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Link Resolvers - Considerations

• Must be OpenURL compliant
• Should be available as a stand-alone product
• Can be a system that is run/managed locally
• Local hardware/software with annual maintenance
  fee
• More flexible more control
• Needs to be able to run on several operating
  systems
• OR a subscription service hosted by
  vendor/provider (ASP Option)
• More feasible for those with limited technical
  staff and hardware
• Vendor supplies support in establishing/maintainin
  g system
• Hosting site should have 24/7 support and
  redundant connectivity to Internet
• Evaluate match of the products sources/targets
  to own collections
• Evaluate customization options of both
  interface (e.g. ranking of results/options
  obtained) and product itself (e.g. preselected
  links only or unlimited customization)
• Evaluate overall price varies widely across
  products

In part, from Harry Samuels Product manager
Endeavor/LinkFinderPlus
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Link Resolvers - Examples

• Standalone Resolvers
• SFX (ExLibris)
• LinkFinderPlus (Endeavor)
• Journal Finder (University of North Carolina
  Greensboro)
• Gold Rush (CARL)
• SirsiResolver (Sirsi)
• OL2 (Fretwell-Downing)
• 1Cate (Openly Informatics)
• ArticleLinker (Serials Solutions)
• LinkSource (EBSCO)
• Integrated Resolvers
• WebBridge (Innovative)
• Horizon Link (Dynix)
• Resolvers in Proprietary Database Systems
• H. W. Wilson
• Cambridge Scientific Abstracts

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OpenURL

• First developed by Oren Beit-Arie ( Ex Libris),
  and Herbert Van de Sompel (Los Alamos National
  Laboratory)
• An accepted standard syntax for creating a link
  between an information source and a link resolver
• The means to pre-define/organize sets of metadata
  elements to use in describing an item/resource
  (e.g. a journal article)
• Also includes the ADDRESS of the link resolver
• Comprises 2 parts
• BASEURL - identifies the Resolver that will
  provide the context sensitive services for the
  OpenURL
• QUERY the DESCRIPTION or metadata attributes
  and values that make up the citation for the
  resource/item

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ANSI Standard OpenURL .1 to OpenURL 1.0

• More genres supported (e.g. Report, Document,
  Dissertation, Patent added)
• Richer data formats supported (e.g. Key Encoded
  Values, XML)
• More complete context descriptors
• More types of transports available (e.g. HTTP Get
  or Post, )
• More controlled evolution

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References

• ANSI/NISO Z39.88-2004 The OpenURL Framework for
  Context-Sensitive Services The
  Key/Encoded-Value (KEV) Format Implementation
  Guidelines - available at http//library.caltech.
  edu/openurl/StandardDocuments/KEV_Guidelines-20040
  211.pdf
• The Lure of Linking. John McDonald Eric F.
  Van De Velde. Library Journal (online) 4/1/2004.
  Available at http//www.libraryjournal.com/articl
  e/CA405398
• OpenURL and OpenURL Framework Demystifying Link
  Resolution - The promise of OpenURL 1.0. Oliver
  Pesch. Available at http//library.caltech.edu/ope
  nurl/Talks/Oliver20Pesch20-20NISO20OpenURL20W
  orkshop-for20print.ppt
• What is OpenURL?. Available at
  http//www.serialssolutions.com/alourl01.asp
• Distributed Systems OpenURL Demonstrator.
  Available at http//www.ukoln.ac.uk/distributed-sy
  stems/openurl/