c2001 Endeavor Information Systems, Inc.

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Linking &

CrossRefHarry E. Samuels

Digital Library Projects CoordinatorEndeavor Information Systems Inc.

c2001 Endeavor Information Systems, Inc.

What Do We Mean By Linking?• We mean linking to full-text• We mean linking to extended

services

Why Is Linking Important?• Because it makes the research

process faster and more efficient

Linking & CrossRef

c2001 Endeavor Information Systems, Inc.

What Does A Linking System Do?

• It accepts metadata from a Source• Based on the metadata and information in

its database, it determines what links should be presented to the user, and it then builds and presents those links.

• Because the library has control over the contents of the database, the linking system should only present links that are relevant and accessible to the user.

Linking & CrossRef

SourceDatabase Linking System

TargetDatabase

Metadata Link-To URL

c2001 Endeavor Information Systems, Inc.

What Is OpenURL?• A syntax for transporting metadata via http

• It looks like this: http://lfp.endinfosys.com?issn=5555-6666&date=2001&volume=1&issue=2&spage=

99

What Is A Link-To URL?• Whatever syntax a target database uses

• It may look like this: http://www.automag.com/AAOWMagazine/2001_aprilmay/pg18.asp

Linking & CrossRef

SourceDatabase Linking System

TargetDatabase

OpenURL Link-To URL

c2001 Endeavor Information Systems, Inc.

What Is In A Source Database?• It could be an abstracting or indexing database like

ProQuest or Web of Science or Silver Platter

What Is In A Target Database?• Full text as in Science Direct or Academic Press or

American Mathematical Society• Extended Services like:

– Document Delivery sites– General interest web sites– Any service for which the system can build a URL

Linking & CrossRef

SourceDatabase Y Linking System Target

Database Y

OpenURL Link-To URL

TargetDatabase X

TargetDatabase Z

Link-To URL

Link-To U

RL

SourceDatabase X

SourceDatabase Z Open

URL

OpenURL

c2001 Endeavor Information Systems, Inc.

What Is the DOI Handle System?

• Managed by International DOI Foundation (IDF)

• Uses Handle Technology from Corporation for National Research Initiatives (CNRI)

Linking & CrossRef

SourceDatabase DOI Handle System

TargetDatabase

DOI Link-To URL

http://dx.doi.org/10.1000/123456

c2001 Endeavor Information Systems, Inc.

What Is CrossRef?• Co-operative effort between 70 learned

publishers• Non-profit trade association• Enables identifier-based linking using DOIs • Registers DOIs and URLs for member

publishers• Provides metadata lookup service to

enable link resolution• Funded by look-up and deposit fees

Linking & CrossRef

CrossRef Collection Service

DOI Handle System

Publisher

Article

Metadata

DOIs

URLs

CrossRef Database

Art

icle

Met

adat

aD

OIs

DO

Is

URLs

CrossRef Query Service

Publisher

Article

Metadata

CrossRef Database

DOIs

c2001 Endeavor Information Systems, Inc.

What Is The Appropriate Copy Problem?

• The DOI Handle System has several inherent problems– It does not know if the user’s library has a

linking server and does not know the information in the linking server’s database.

– It only registers URLs for rights holders (publishers) and knows nothing about aggregator sites or local copy (electronic or hardcopy).

Linking & CrossRef

c2001 Endeavor Information Systems, Inc.

Appropriate Copy Prototype• A prototype group led by Dale

Flecker of Harvard that is testing an architecture that will put a library’s linking server back in the loop.

Linking & CrossRef

SourceDatabase DOI Handle System

PublisherDatabase

DOI Link-To URL

AggregatorDatabase

Local Copy

Linking Server

DO

I in

Ope

nUR

L

CrossRef

DOI in OpenURL

Metadata

Link-To URL

Link-To URL

Link-T

o URL

DO

I

c2001 Endeavor Information Systems, Inc.

Endeavor Linking Products• LinkFinder

– Packaged with Citation Server– Accepts metadata passed to it

from Citation Server interface and provides links to full-text (one-way linking)

– Extended service links will also be added

– Scheduled release is Summer 2001

c2001 Endeavor Information Systems, Inc.

Endeavor Linking Products• LinkFinderPlus

– Packaged with ENCompass AND sold as stand-alone product

– Accepts OpenURL from any interface including ENCompass

– Builds link-to URLs– Will be able to serve as local resolver

for appropriate copy resolution– Scheduled release is End-Of-Year

2001 (as stand-alone and packaged with ENCompass)

c2001 Endeavor Information Systems, Inc.

Important URLs• NISO Committee AX on

OpenURLhttp://library.caltech.edu/openurl

• CrossRefhttp://www.crossref.org

• The Digital Object Identifier Systemhttp://www.doi.org/

c2001 Endeavor Information Systems, Inc.

Endeavor’s ENCompass