28 april 2004second nordic conference on scholarly communication 1 citation analysis for the free,...

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Citation Analysis for the Free, Online Literature

Tim Brody

Intelligence, Agents, Multimedia Group

University of Southampton

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Content

• Current services for Open Access Literature

• Institutional Archives Registry• Metadata Harvesting through Celestial• Citebase Search

– Citation Linking– Search and Navigation Service

• Web Impact as a predictor of Citation Impact

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Institutional Archives Registry

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Sites in the IAR

• Things we want to know:– GNU EPrints sites– Other research collections (Other Archives, Open

Journals)– BOAI 1. vs BOAI 2.

• A submission form consisting of:– URL, Name, OAI URL, Country, ‘type’, full-text,

software• Can’t (yet) track full-texts• (Create a master-list so archives only register-

once?)

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Celestial

• Designed to:– Be an abstraction over OAI-PMH versions– Caching OAI metadata records

• Technological questions:– How big can the OAI-PMH go (ok for 5 million

records so far)– How reliable are OAI-PMH implementations

• Feeds Citebase, IAR, some external users

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Services for Open Access Literature

Self-Archived Full-texts (Pre/Post-prints)Open Access Publishing

Citation Analysis/Linking Services(Citebase / Citeseer / OpenURL / DOI)

Version Linking Services

Search EnginesNavigation Tools

Analysis & Assessment

Citebase

Citeseer

Google

BM

C

arXiv.org

OA

I-PM

H T

ransport

OA

Ister

Scirus

n.b. Scirus/OAIster aren’t citation-analysis aware yet, Googleindexes Citeseer. Not an exhaustive list …

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Citation Analysis & Linking

• A citation is a reference from one work to another [as a hyperlink: a citation link]

• Citation analysis uses citation relationships to analyse patterns in research

• As a graph a work (paper, book etc.) is a vertex and a citation an edge

• ‘Bibliometrics’– (study of patterns in literature)

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Digitometric/Infometric Analysis

• Bibliometrics for the online age

• Couple citation analysis with Web analysis– (how many times has x been accessed?)

• Similar to readership studies, but easier to survey and more comprehensive– (though subject to the same problems of

copies being re-distributed, multiple accesses etc.)

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Citebase Search

Repositories

Metadata Harvest(OAI-PMH)

Full-text Harvest

Meta Database

ReferencesDatabase

CitationDatabase

WebInterface

OAI-PMHInterface

Citebase

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Citation Linking

• Retrieve and cache full-texts– LaTeX, PDF, XML

• Extract reference list

• Extract individual references

• Parse references into components– Author, year, title, journal, volume, pagination

• Store in structured database

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Citebase Search

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Citebase Search:Navigation by Citation Links

Current Article Co-cited

Article withreference list

Referencelink

Future

Past

Related

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Predicting Citation Impact

• The Web gives us access to new metrics– Download/access frequency

• Can early-day ‘download’ frequency give an indication of longer-term citation frequency?

• (Web logs from the UK arXiv.org mirror, Citation data from Citebase Search)

• Pearson correlation after 6 months of web logs = 0.42 for the High Energy Physics sub-arXiv

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0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 100 200 300 400 500 600 700 800Days since deposit

Cor

rela

tion

(r)

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Assessing Research(ers)

• Citation Impact– By-Paper, Author, [Journal, Institution]

• Web Impact– Predictor of citation-impact, combine with

citation-impact

• Search Engines

• More detailed research assessment

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Comparing Online/Offline Impact

• Using ISI CD-ROM data• Use Web crawlers to find ‘online’ articles• Compare citation impact of online and

offline articles– By discipline, by journal, by author?

• Initial results for Physics show 2-3x increase– arXiv.org

• Southampton, U. Quebec, Oldenburg (de)

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Relevant Web Pages

• EPrints – http://www.eprints.org/– IAR: http://archives.eprints.org/

• Citebase Search– http://citebase.eprints.org/

• Celestial– http://celestial.eprints.org/

• Correlation Generator– http://citebase.eprints.org/analysis/correlation.php

• Tim Brody <tdb01r@ecs.soton.ac.uk>