Introduction to Introduction to Linking Linking

Technologies Technologies & OpenURL& OpenURL

Lori Jean Ostapowicz CritzLori Jean Ostapowicz Critz

Georgia Institute of Georgia Institute of TechnologyTechnology

5/20/045/20/04

Linking TechnologyLinking Technology Permits context-sensitive linking Permits context-sensitive linking

between various web-based resources between various web-based resources

Allows libraries to combine electronic Allows libraries to combine electronic resources (full-text journals, abstracting resources (full-text journals, abstracting & indexing databases, citation & indexing databases, citation databases, online library catalogs, databases, online library catalogs, interlibrary loan/document delivery interlibrary loan/document delivery systems, search engines) to function as systems, search engines) to function as a cohesive, one-stop reference systema cohesive, one-stop reference system

OpenURL FrameworkOpenURL Framework Provides a means of Provides a means of DESCRIBINGDESCRIBING a a

reference resource along with a reference resource along with a description of the description of the CONTEXTCONTEXT of the of the referencereference

Also defines methods of Also defines methods of TRANSPORTINGTRANSPORTING these descriptions between networked these descriptions between networked systemssystems

Used to Used to REQUESTREQUEST SERVICESSERVICES pertaining pertaining to the referenced resources that are to the referenced resources that are appropriate for the requestor (i.e. enables appropriate for the requestor (i.e. enables context-sensitive linking from a reference context-sensitive linking from a reference in a scholarly system to resources in a scholarly system to resources relevant to the reference)relevant to the reference)

OpenURL OpenURL FrameworkFramework

A user clicks a link or a button in an HTML page A user clicks a link or a button in an HTML page (usually in an abstracting & indexing database or in a (usually in an abstracting & indexing database or in a reference list of an electronic journal article)reference list of an electronic journal article)

As a result of activating the link or button, a As a result of activating the link or button, a description of the scholarly resource (such as a description of the scholarly resource (such as a journal article) is transported (e.g. via HTTP(S) GET journal article) is transported (e.g. via HTTP(S) GET or POST) to a LINKING SERVER along with or POST) to a LINKING SERVER along with information about the dynamic context of the information about the dynamic context of the referencereference

This dynamic context enables a list of relevant This dynamic context enables a list of relevant services, appropriate to the user, to be provided services, appropriate to the user, to be provided

The LINKING SERVER and its RESOLVER SOFTWARE The LINKING SERVER and its RESOLVER SOFTWARE processes the description/information to provide this processes the description/information to provide this list of options/services (full-text; print holdings ; list of options/services (full-text; print holdings ; interlibrary loan, …)interlibrary loan, …)

How Does the System How Does the System Work?Work?

OpenURL-enabled Library Linking System

A & I Databases

OPAC Publisher sites

OPAC

PUBLISHER SITES

INTERLIBRARY LOAN

Aggregated Databases

Begins with SOURCES that can send an OpenURL to the Linking System/server (Where the user begins the search!)

The System evaluates the ‘request’ and looks for options that can be provided for the desired item.

Aggregated Databases

Subscription Agents

Ends at TARGETS that lead to the desired item or presents alternatives for finding it. (Where the user lands!)

Full textDBs

Full textDBs

More Publisher

sites

More Publisher

sites

GoogleGoogle

ISIISI

LibraryLibrary A&IserviceA&I

service

Publishersites

Publishersites

IngentaIngenta

Link resolvers manage the linking process …

Link Resolver

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.

Adapted from Oliver PeschChief Architect, EBSCO Publishing

Full textDBs

Full textDBs

OtherPublisher

site

OtherPublisher

site

GoogleGoogle

ISIISI

LibraryLibrary A&IserviceA&I

service

Publishersites

Publishersites

IngentaIngenta

User

A

ALibrary subscribes

Pay per view$$$

Without a link resolver the user may notaccess the appropriate (i.e. ‘free’ full-text) copy

With a predefined link, the user may be presented with a link and not have a choice where that link goes

Adapted from Oliver PeschChief Architect, EBSCO Publishing

Full textDBs

Full textDBs

OtherPublisher

sites

OtherPublisher

sites

GoogleGoogle

ISIISI

LibraryLibrary A&IserviceA&I

service

Publishersites

Publishersites

IngentaIngenta

User

A

ALibrary subscribes

Pay per view$$$

LinkResolver

With a link resolver, the library candetermine which copy is appropriate

With the resolver, the library can control where the link goes and get the user to the appropriate copy.

As long as the A&I service knows the user/library has a resolver and where it is, it can create the link.

Adapted from Oliver PeschChief Architect, EBSCO Publishing

Components of Linking Components of Linking SystemSystem

OpenURL- enabled Content ProvidersOpenURL- enabled Content Providers Called SOURCES or REFERRANTS or REFERRING Called SOURCES or REFERRANTS or REFERRING

SOURCESSOURCES Generate the OpenURL to start the processGenerate the OpenURL to start the process Can also serve as targets (e.g. Proquest) if linked TO by link Can also serve as targets (e.g. Proquest) if linked TO by link

resolver/serverresolver/server

Data about the CollectionData about the Collection Inaccurate data leads to linking errors, incomplete holdings Inaccurate data leads to linking errors, incomplete holdings

information, and inaccurate availability statementsinformation, and inaccurate availability statements

Resolver Resolver Performs the comparison between the collection /holdings Performs the comparison between the collection /holdings

and the desired cited itemand the desired cited item Displays options/results (e.g. links to full-text or OPAC) and Displays options/results (e.g. links to full-text or OPAC) and

additional features (e.g. links to ILL/document delivery, additional features (e.g. links to ILL/document delivery, Google search, Endnote connection)Google search, Endnote connection)

Linking Technology in Linking Technology in Action …Action …

A search in CSA Sociological Abstracts (the SOURCE) leads a user to a citation for a desired item …

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

Issue:4

Date: Aug. 2001

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.

The OpenURL that describes the citation would look something like this:

http://VD2YN4ULBU.linkresolver.com/?atitle=Cultural+Values+and+Happiness%3A++An+East-West+Dialogue&volume=141&issue=4&date=2001&spage=477&aulast=Lu&aufirst=Luo&issn=0022-4545&title=The+Journal+of+social+psychology

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.

Description/Context Description/Context ObjectObject

ServiceType

Referent

Resolver

ReferringEntity

Referrer

Requester

AdministrativeVersion control, character encodings,

timestamp, etc.

Item being referenced. (e.g. bibliographic reference in full text article)

“User” making the request

Service creating the link. (e.g. where the user found the reference)

The item which contains the reference. (e.g. the article in which the bibliographic

reference was found)

The target of the link - the link server of the user’s institution

The desired services from the Resolver. ( Full text, ILL, Abstract, etc.)

Description of the

referenced item

and the ‘context’ of

the referencing

action …

The Link Resolver compares the data about the item described in the OpenURL with data (knowledge base) about what is held/owned/accessible in the library’s 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

Resolver

The Link Resolver then displays the options/services available to the user (based on the metadata encoded in the OpenURL).

The user then selects the best option (full-text, link to print holdings record, ILL …) and is presented that option.

The ‘options’ that can be provided vary with the resolver systems used – and are quite diverse!

Link Resolvers - Link Resolvers - ConsiderationsConsiderations

Must be OpenURL compliantMust be OpenURL compliant Should be available as a stand-alone productShould be available as a stand-alone product Can be a system that is run/managed locallyCan be a system that is run/managed locally

Local hardware/software with annual maintenance feeLocal hardware/software with annual maintenance fee More flexible; more controlMore flexible; more control Needs to be able to run on several operating systemsNeeds to be able to run on several operating systems

OR a subscription service hosted by vendor/provider (ASP OR a subscription service hosted by vendor/provider (ASP Option)Option) More feasible for those with limited technical staff and hardwareMore feasible for those with limited technical staff and hardware Vendor supplies support in establishing/maintaining systemVendor supplies support in establishing/maintaining system Hosting site should have 24/7 support and redundant connectivity to Hosting site should have 24/7 support and redundant connectivity to

InternetInternet Evaluate ‘match’ of the product’s sources/targets to own Evaluate ‘match’ of the product’s sources/targets to own

collectionscollections Evaluate ‘customization’ options – of both interface (e.g. Evaluate ‘customization’ options – of both interface (e.g.

ranking of results/options obtained) and product itself (e.g. ranking of results/options obtained) and product itself (e.g. preselected links only or unlimited customization)preselected links only or unlimited customization)

Evaluate overall price – varies widely across productsEvaluate overall price – varies widely across products

In part, from Harry Samuels – Product manager: Endeavor/LinkFinderPlus

Link Resolvers - Link Resolvers - ExamplesExamples

Standalone ResolversStandalone Resolvers SFX (ExLibris)SFX (ExLibris) LinkFinderPlus (Endeavor)LinkFinderPlus (Endeavor) Journal Finder (University of North Carolina – Journal Finder (University of North Carolina –

Greensboro)Greensboro) Gold Rush (CARL)Gold Rush (CARL) SirsiResolver (Sirsi)SirsiResolver (Sirsi) OL2 (Fretwell-Downing)OL2 (Fretwell-Downing) 1Cate (Openly Informatics)1Cate (Openly Informatics) ArticleLinker (Serials Solutions)ArticleLinker (Serials Solutions) LinkSource (EBSCO)LinkSource (EBSCO)

Integrated ResolversIntegrated Resolvers WebBridge (Innovative) WebBridge (Innovative) Horizon Link (Dynix)Horizon Link (Dynix)

Resolvers in Proprietary Database SystemsResolvers in Proprietary Database Systems H. W. WilsonH. W. Wilson Cambridge Scientific AbstractsCambridge Scientific Abstracts

OpenURLOpenURL

First developed by Oren Beit-Arie ( Ex Libris), and First developed by Oren Beit-Arie ( Ex Libris), and Herbert Van de Sompel (Los Alamos National Herbert Van de Sompel (Los Alamos National Laboratory)Laboratory)

An accepted “standard” syntax for creating a link An accepted “standard” syntax for creating a link between an information source and a link resolverbetween an information source and a link resolver

The means to pre-define/organize sets of metadata The means to pre-define/organize sets of metadata elements to use in describing an “item”/resource (e.g. a elements to use in describing an “item”/resource (e.g. a journal article)journal article)

Also includes the ADDRESS of the link resolverAlso includes the ADDRESS of the link resolver

Comprises 2 parts : Comprises 2 parts : BASEURL - identifies the Resolver that will provide BASEURL - identifies the Resolver that will provide

the context sensitive services for the OpenURLthe context sensitive services for the OpenURL QUERY – the DESCRIPTION or metadata attributes QUERY – the DESCRIPTION or metadata attributes

and values that make up the citation for the and values that make up the citation for the resource/itemresource/item

ANSI Standard: ANSI Standard: OpenURL .1 to OpenURL 1.0OpenURL .1 to OpenURL 1.0

More genres supported (e.g. More genres supported (e.g. Report, Report, Document, Dissertation, PatentDocument, Dissertation, Patent added)added)

Richer data formats supported (e.g. Richer data formats supported (e.g. Key Key EncodedEncoded Values, XMLValues, XML))

More complete ‘context’ descriptorsMore complete ‘context’ descriptors

More types of transports available (e.g. More types of transports available (e.g. HTTP Get or Post,HTTP Get or Post, ) )

More controlled ‘evolution’More controlled ‘evolution’

ReferencesReferences ANSI/NISO Z39.88-2004: The OpenURL Framework ANSI/NISO Z39.88-2004: The OpenURL Framework

for Context-Sensitive Services – The Key/Encoded-for Context-Sensitive Services – The Key/Encoded-Value (KEV) Format Implementation Guidelines - Value (KEV) Format Implementation Guidelines - available at available at http://library.caltech.edu/openurl/StandardDocuments/http://library.caltech.edu/openurl/StandardDocuments/KEV_Guidelines-20040211.pdfKEV_Guidelines-20040211.pdf

““The Lure of Linking”. John McDonald & Eric F. Van The Lure of Linking”. John McDonald & Eric F. Van De Velde. Library Journal (online); 4/1/2004. Available De Velde. Library Journal (online); 4/1/2004. Available at: at: http://www.libraryjournal.com/article/CA405398http://www.libraryjournal.com/article/CA405398

““OpenURL and OpenURL Framework: Demystifying Link OpenURL and OpenURL Framework: Demystifying Link Resolution - The promise of OpenURL 1.0”. Oliver Pesch. Resolution - The promise of OpenURL 1.0”. Oliver Pesch. Available at Available at http://library.caltech.edu/openurl/Talks/Oliver%20Peschttp://library.caltech.edu/openurl/Talks/Oliver%20Pesch%20-%20NISO%20OpenURL%20Workshop-for%20prh%20-%20NISO%20OpenURL%20Workshop-for%20print.pptint.ppt

““What is OpenURL?”. Available at What is OpenURL?”. Available at http://www.serialssolutions.com/alourl01.asphttp://www.serialssolutions.com/alourl01.asp

““Distributed Systems OpenURL Demonstrator”. Distributed Systems OpenURL Demonstrator”. Available at Available at http://www.ukoln.ac.uk/distributed-systems/openurl/http://www.ukoln.ac.uk/distributed-systems/openurl/