Getting technical: reference linking(or, “Well, I wouldn’t start from here…”)

Tom Bishop

Information Services Manager,The Royal College of Surgeons of England Library

3rd June, 2003

Getting technical

On the agenda (possibly)...

Getting technical

DOI

CrossRef

OpenURLSFX

Balsa

OPACs

1CATE

SWALK

Blink 182P45

EIEIO

OK – “Com-pyoo-tur”…

Getting technical

The key players

How do we get access to journals and citations?

• Publishers – their own web sites and services• Full text aggregators – Journals@Ovid, ProQuest, etc.• ‘Hosts’ – SwetsWise, Ebscohost, HighWire, etc.• ‘Secondary’ (A&I) databases – PubMed, Cambridge Scientific Abstracts, etc.• … and libraries!

Getting technical

Reference linking: what do we mean?

“The ability to go directly from a citation to the work cited” (Priscilla Caplan)

• Links among and between journal articles• Links from bibliographic citations to journal articles• Seamless, easy access allowing the user to link quickly and directly to any document they want

Getting technical

Getting technical

…And you may ask yourself - “Well, how did I get here?”

“Internal linking”• Links contained within one service - e.g. from a reference in a full-text aggregator’s service to the text of an article held in the same service.

“External linking”• Takes the user out of a service to somewhere else - e.g. from a database to a publisher’s website, from one publisher’s website to another’s, etc.

Getting technical

Getting technical

Getting technical

CrossRef

External linking initially largely dependent on bilateral agreements.

CrossRef is:

• “…a collaborative linking service”

• a membership network, not a product

Getting technical

CrossRef

Over 200 publishers registered

Agents - HighWire, IngentaAffiliates - Ebsco, TDNet, SwetsBlackwellLibraries

7.8 million content items registered across over 7000 journals

How does it work?

Getting technical

Take a step back…

A link:

http://www.rcseng.ac.uk/services/library

• ‘Static’ – link is computed in advance

• Not necessarily persistent - relates to a specific location defined at a specific time

Getting a bit more technical

Getting a bit more technical

DOI: Digital Object Identifier

A unique identifier assigned to a digital object.

• A way of accessing an object (e.g. a full text article) without having to know its URL - the DOI identifies the object itself, not the place where it is stored.

• Persistent - as long as the object exists, so does the DOI.

Getting even more technical

DOI: Dumb Old Identifier

“Dumb” number - doesn’t relate to the object, couldn’t be guessed - like a phone number.

10.1000/123456789

Getting even more technical

Prefix - given to the rights owner e.g. the publisher

Suffix - any unique alphanumeric string

e.g. 10.1074/jbc.M004545200

CrossRef and DOI

• Publisher participating in CrossRef creates unique DOI for article.

• Associates it with:• the articles’s metadata e.g. journal title/ISSN, vol., issue, pages, title, author, AND• the URL where it resides.

• Submits all this to CrossRef for registration in a central directory.

Getting even more technical

Getting even more technical

Getting even more technical

Getting even more technical

Getting even more technical

Getting even more technical

Getting even more technical

CrossRef and DOI: the benefits

• Participants can link in to the article by retrieving from CrossRef the DOI that links to it.• Publishers can link outward from an article’s citations to any content registered by CrossRef.• Single agreement rather than many bilateral ones.• Drives up journal traffic.• If the location of an article changes, all the publisher has to do is update the URL in the CrossRef directory.• If the journal changes publisher, the DOI stays the same.

Getting a bit less technical, hopefully

…But along comes the librarian with his bucket of cold water...

• Many articles do not have a DOI, and there are publishers not involved in the scheme.

• “With CrossRef it only takes a click or two to get to the full text, either as an authenticated user or through pay-per-view services.”

The cat/pigeons slide

Is this good enough??

Work versus manifestation

A CrossRef DOI represents the work (the authoritative version of the article as published) itself, but not manifestations (different versions) of that work.e.g. the print/PDF/HTML versions may differ.

Partly soluble in this example - publisher’s page to which the DOI for that article resolves can point to different versions.

But then we hit…

Getting a bit more technical again

The dictatorship of the publishariat

Van der Sompel: “Dictated linking”

• ‘Target’ (i.e. where the user ends up) is dictated by the link provider.

• Ability to link and range of targets depends on the link provider’s collections or agreements.

• Bypasses the local environment - the link provider tells the user where to go, and the local institution cannot influence that.

Why is this important?

That’s not a real word,is it?

Getting even more technical

Getting even more technical

Getting even more technical

The issue of ‘appropriate copy’

CrossRef DOIs resolve to a publisher’s ‘response page’ - usually a full bibliographic citation, often an abstract, and a mechanism to get to the full text. But the user will usually be denied access to full text if they don’t have a personal or institutional subscription. Pay-per-view may be offered but…

Getting a bit more technical again

…the user may in fact be able to get hold of the article from a different source as a result of their library affiliation.

Appropriate sources and services

• Another database, aggregator or host to which the library subscribes• The library’s print holdings• Document delivery/ILL - the library’s own or a specific provider

Solution = ‘Context-sensitive linking’

• Also allows for ‘Extended services’ - internet search, link from OPAC book record to book review on the web, etc.

Getting a bit more technical again

SFX (Ex Libris)

First product to attempt to solve these problems.

How does it work?

Link source: the information resource where the user begins, e.g. a citation in a database or within an article, or a journal record in an OPAC.

Link target: the information resource where the user ends up, e.g. publisher response page, TOC page, journal home page etc.

Getting even more technical

Pretty technical

Getting even more technical

Getting even more technical

Getting even more technical

Getting even more technical

Getting even more technical

Hang on…

… How does the link resolver ‘know’ about the article required?

Rather than a static link to a particular target, the link source provides a ‘hook’ that gives information, in the form of metadata, about the article.

When a user clicks the ‘SFX’ button, an OpenURL is created.

Getting even more technical

OpenURL

A way of transmitting metadata in a URL - essentially a transport system.

http://LinkFinderPlus.library.edu?genre=article&issn=12345678&volume=99&issue=1&date=20020101&spage=27&atitle=What Is An OpenURL&title=Harry's White Papers

As technical as it gets

‘Base URL’: web address of the link resolver i.e. the address to which the Open URL is being sent

‘Query’: the metadata that the link resolver uses to identify and link to appropriate targets

OK, but…

… How does the information resource provider in whose service the user has found the citation (e.g. database provider, journal publisher, host, OPAC, etc.) ‘know’ the affiliation of the user and therefore which link resolver to send the OpenURL to?

• OpenURL-aware sources (e.g. ScienceDirect, SwetsWise, Ovid databases) - link resolver address provided in institutional profile.• Use of ‘cookie pushers’. • Local solutions like IP recognition.

As technical as it gets

OpenURL and CrossRef/DOI

Complement each other when used in conjunction.

http://LinkFinderPlus.library.edu?genre=article&issn=12345678&volume=99&issue=1&date=20020101&spage=27&atitle=What Is An OpenURL&title=Harry's White Papers&id=doi:123/456789

• Link resolver can point the user to a persistent object as an appropriate copy.• DOI is attached to metadata in the CrossRef database – no need to update a local link resolver if things change.

As technical as it gets

Everybody’s doing it…

LinkFinderPlus (Endeavor)

1CATE (Openly Informatics)

WebBridge (Innovative)

LinkSource (Ebsco)

Linksolver (Ovid)

Balsa (EDINA)

Getting less technical again

Open URLs and context-sensitive resolution - a good example

Andy PowellOpenResolver: a simple OpenURL resolver.

Articlehttp://www.ariadne.ac.uk/issue28/resolver/

Walkthroughhttp://www.ukoln.ac.uk/distributed- systems/openurl/

Getting less technical again

The benefits...• Appropriate copy and extended services - decided at a local level to maximise usage.

• Better user interface - users look for SFX (or whatever) button wherever they are, cuts out wild goose chases.

• Links aren’t computed until the user clicks – dynamic “just-in-time” linking reduces response times.

• ‘Political’ - puts the library at the centre of searching and retrieval.

Not too technical

…and the costs?

• Financial - dependent on product and institution

• Time and effort

“The SFX services… are only as good as the information provided by the librarian. The more detailed the information, the better the level of granularity for linking.” (Jenny Walker, SFX)

“An OpenURL resolver is never better than the knowledge base behind it.” (Eric Hellman, Openly)

Not too technical

Future developments

• National or centralised resolvers?

• Multiple resolution of DOI

Technical for the last time

“I believe OpenURL resolution is going to become as obvious a necessity for navigating through and across databases as online catalogs were for libraries in the 80's.” (Chuck Hamaker, UNCC)

Thank you.

(Brought to you by the letters D, O and I and the number 10.1000/123456789)

That’s all, folks