Bibliometrics :Now There are Options

Elaine M. Lasda BergmanBibliographer for Social Welfare and Dewey ReferenceDewey Graduate LibraryApril 28, 2011

What is bibliometrics?

Scholarly communication Influence of articles, journals, scholars

The birth of citation analysis

Eugene Garfield Citation indexes and JCR Better coverage on hard sciences than on

social sciences and worse still on humanities

Garfield’s metrics

Citation count Impact Factor Immediacy Index Citation Half-Life

Citation count

Number of times cited within a given time period Author Journal

Does not take into account Materials not included in citation database Self citations

Impact factor

Measures “impact” of a journal (not an article) within a given subject

Formula is a ratio: Number of citations to a journal in a given year

from articles occurring in the past 2 years Divided by the number of scholarly articles published in the journal in the past 2 years

Concerns with impact factor

Cannot be used to compare cross disciplinary (per Garfield himself) due to different rates of publication and citation

Two year time frame not adequate for non-scientific disciplines

Coverage of some disciplines not sufficient in the ISI databases

Is a measure of “impact” a measure of “quality”?

Immediacy index

What it’s supposed to measure: how quickly articles in a given journal have an impact on the discipline

Formula: the average number of times an article in a journal in a given year was cited in that same year

Citation Half-Life

What it’s supposed to measure: duration of relevance of articles in a given journal

Formula: median age of articles cited for a particular journal in a given year

TWENTY FIRST CENTURY TOOLS

Influence of Google Page Rank

Eigenvector analysis: “The probability that a researcher, in documenting his or

her research, goes from a journal to another selecting a random reference in a research article of the first journal. Values obtained after the whole process represent a ‘random research walk’ that starts from a random journal to end in another after following an infinite process of selecting random references in research articles. A random jump factor is added to represent the probability that the researcher chooses a journal by means other than following the references of research articles.” (Gonzales-Pereira, et.al., 2010)

Sources Using ISI Data

Journalranking.com

Journal Ranking.com uses ISI data and eigenvector (PageRank) algorhythm to create one’s own categories Can assign different weights to citations from the

same journal, the same category and from other categories or only whithin a specific list

Not updated since 2005 http://libguides.library.albany.edu/content.php?pi

d=60086&sid=441804

Eigenfactor.org http://libguides.library.albany.edu/content.php?pid=60086&sid=441804

Uses ISI data Similar to PageRank Listed in JCR as of 2009 Eigenfactor Score :

Influence of the citing journal divided by the total number of citations appearing in that journal

Example: Neurology (2006): score of .204 = an estimated 0.2% of all citation traffic of journals in JCR (Bergstrom & West, 2008).

Larger journals will have more citations and therefore will have larger eigenfactors

Article Influence Score

From Eigenfactor: measure of prestige of a journal Average influence, per article of the papers on a

journal Comparable to the Impact Factor Corrects for the issues of journal size in the raw

Eigenfactor score Neurology’s 2006 article influence score = 2.01. Or

that an avg. article in Neurology is 2X as influential as an avg. article in all of JCR

ScienceWatch

Provides “quick and dirty” articles on hot researchers, trending research topics, institutions and journals

Much on this site (in-cites, etc) are now parts of analytical products being sold byThompson; no longer free

There are still some good articles, but not searchable, hit or miss information

http://sciencewatch.com/dr/sci/11/

New sources for citation information Google Scholar Scopus

Scopus: alternate database of citation data

Review panel, i.e., quality control Bigger field than ISI: covers all the journals in

WoS and more Strongest in “hard”sciences”, ostensibly

improved social science coverage, arts and humanities: are “getting there”

Algorithmically determined with human editing

Google Scholaralternate database of citation data

No rhyme or reason to what is included Biggest source of citation data Foreign language sources Sources other than scholarly journals Entirely algorithmically determined, no

human editing

Scopus analytics

SNIP SJR/SCIMago Author Evaluator

SNIP (Source Normalized Impact Per Paper)

Journal Ranking based on citation analysis with adjustments for the frequency of citations of the other journals within the field (the field is all journals citing this particular journal)

SNIP is defined as the ratio of the journal’s citation count per paper and the citation potential in its subject field. (Moed, 2009)

http://www.scopus.com/home.url

SJR:SCImago Journal Rank

What it’s supposed to measure: “current “average prestige per paper”

SCImago website uses journal/citation data from Scopus, and is also available from scopus db

Formula: citation time window is 3 years instead of 2 like JIF

Corrections for self citations Strong correlation to JIF

SCImago Journal Rank

Prestige factors include: number of journals in db, number of papers from journal in database, citation numbers and “importance” received from other journals: size dependent: larger journals have greater prestige values

Normalized by the number of significant works published by the journal: helps correct for size variations

Corrections made for journal self citations

Scopus Author Evaluator

Breakdown of documents by source H-index Citations per year (graph)

Google Scholar

Publish or Perish CIDS

Publish or Perish

Provides a variety of metrics for measuring scholarly impact and output.

More useful for metrics on authors than journals or institutions

Uses Google Scholar citation information Useful for interdisciplinary topics, fields relying

heavily on conference papers or reports, non-English language sources, new journals, etc.

Continuously updated since 2006

Publish or Perish Metrics

Basic metrics: # papers, #citations, active years, years since

first published, average #of citations per paper, average # of citations per year, average # citations per author, etc.

Complex metrics H index (and its many variations, mquotient, g-

index (corrects h-index for variations in citation patterns), AR index, AW index

Does not have any corrections for SELF CITATIONS

CIDS

Measures output of authors for prestige and influence

Similar to PoP Corrects for Self-Citations Uses Google Scholar data

CIDS metrics

Citations per year, h-index, g-index, total citations, avg cites per paper, self citations included and excluded, etc.

http://cids.di.fc.ul.pt/cids_3_0/info.php?acc=25201514041114103161

Mesur

Metric based on usage, citation and bibliographic data

Uses its own datbases of documents/metadata/reference, users & authors, “usage events” and citations

Project seems to be dead?

Considerations

Don’t measure an individual journal’s impact by the metrics for the entire journal

Cluster of years of citations Negative citations A few high impact citations or a lot of low

impact ciations Source of citing documents

Foreign, conference proceedings, traditional

Questions???