CrossRef Case StudyElsevier & Local Hosting

Chris ShillumKaren Hunter

Elsevier, CrossRef & IDF

• largest depositor of metadata & DOIs thus far (about 1 million articles)

• member of the IDF and CrossRef boards

• start-up lender to both IDF and CrossRef

• have clear policy that want links via CR

• bottom line: heavily invested and dedicated to making CrossRef and DOI work

Elsevier and Uses of DOI

• ScienceDirect primary journals -- SD & SDOS

• secondary (a & i) services – on ScienceDirect– elsewhere on the Web (Embase.com)

• BioMedNet, ChemWeb, EiVillage

• Endeavor

• MDL

Local Hosting

• Elsevier receives a copy of the full CrossRef metadata database at ScienceDirect in Dayton (Lexis-Nexis)

• use of the database is restricted to extraction of the DOI for ES products

• we pay for all non-ES records delivered, whether used or not

• matching is done on-the-fly

Primary Journals on SD

• depositing all ES articles on SD (now 1995+, but backfile project underway)

• not yet deposited third party publishers

• therefore, only linking from references in ES titles

• reminder: you can only link out from references in articles that have themselves been deposited with CrossRef

Secondary Services

• on ScienceDirect -- a combination of services owned by Elsevier (Compendex, Embase, Beilstein, Geobase, Biobase, etc.) and those licensed in (Biosis, Inspec, EconLit, etc.)

• links are made to all records found in the CrossRef metadata database

Other Services

• links not yet in place for non-ScienceDirect remote services (e.g., SDOS inward and outward links, BioMedNet, Endeavor, etc.)

• developments under way for DOI retrieval for all services

Why Local Host?

• Better fit with existing linking infrastructure

• Maintain dynamic, pre-resolved linking– CrossRef 1.0 designed for (semi-)static, pre-resolved

links

• Avoid building DOI lookup caching infrastructure

• No quality of service dependency

• Single CrossRef interface for multiple product platforms

ScienceDirect/CrossRef Implementation path

• DOI assignment scheme– Based on existing PII identifiers, assigned to all our

articles back to 1995

• CrossRef batch submission– Based on existing “Article Catalogue”

– Convert to CrossRef DTD and add DOIs

• Local-hoster batch receipt– Based on existing gateway architecture

– Covert CrossRef batches and load to linking table

• Response page– Modify to add bibliographic info and CrossRef info

ScienceDirect

ContentDatabase

ContentFabrication

WebInterface

Content

GatewayInfrastructure

ArticleCatalogue

LinksDatabase

CrossRefComponents

CrossRefBatch

Loader

CrossRefBatch

Submission

CrossRef

GatewayPartner

ScienceDirect/CrossRef Architecture

Lessons learned along the way

• Inventory management difficult– Both inbound and outbound

• Pain to parse local loader batch logs

• Testing (of outbound links) a difficult, manual process

Still to do

• “Outward linking hub”– Provide access to links database for other Elsevier

platforms

– Provide access to links database to local systems customers

• Multi-publisher CrossRef feed– Agent service for hosted content

http://www.sciencedirect.com