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Bibliometrics: an overview
Claudia Cavicchi
Biblioteca Clinica F. Bianchi
claudia.cavicchi@unibo.it
Article metrics
Author metrics
Journal metrics
New metrics
Bibliometrics: an overview
Journal of citation reports
SNIP (Scopus )
Scimago (Scopus)
Web of Science
Google Scholar
Scopus
Web of Science
Scopus
Google Scholar
Impactstory
Social bookmarking
Social networks
Agenda
Why bibliometrics
Carrying out research and communicating the results go hand in hand.
Why bibliometrics
Why bibliometrics
XX century :birth of new media for
communication
communication +
exchange of ideas =
advancement of knowledge .
Knowledge production, acquisition
and management are a source of
wealth.
Why bibliometrics
Why bibliometrics
Governements detect areas of excellence in order to
distribute the funds in the best way.
International
competitiveness
Why bibliometrics
Why bibliometrics
Universities must evaluate their
performance.
Research performance helps to inform strategic decisions about what
areas of research to support or build
Why bibliometrics
How much research is conducted?
What is its impact?
How many of the faculty members’ articles are
published in first-class journals ?
Is that number of publications increasing or
decreasing?
Why bibliometrics
Why bibliometrics
bibliometrics Peer review
Which instruments?
Why bibliometrics: Peer review
Peer review is the evaluation of creative work or
performance by other people (reviewers) in the
same field in order to maintain or enhance the
quality of the work or performance in that field.
Single-blind
Author's name is known to the auditor
while reviewer’s name
remains unknown to the author. It is the
most widespread formula but also the
most subject to criticism for its
subjectivity.
Double-blind
Author’s name and the reviewer’s name
are both kept secret.
This method should ensure an
independent assessment .
However it is very easy to locate the
author of a particular work…..
Why bibliometrics: Peer review
Subjectivity
Conflict of interest
Insufficient
expertise
Favoritism
Why bibliometrics: Peer review cons
Why bibliometrics: (open)peer review
Why bibliometrics: (open)peer review
« the application of statistical and
mathematical methods arranged to define
the processes of written communication
and the nature and development of
scientific disciplines counting techniques
and analysis of such communication»
Pritchard A, Statistical bibliography of
bibliometrics, Journal of documentation
1969;29(4):348-349
What’s bibliometrics
What’s bibliometrics
Bibliometrics doesn’t measure the quality of researcher work but only citations to the work.
Bibliometric data help assess research performance
Why bibliometrics
Why bibliometrics
objective’ method (rather than relying
solely on qualitative measures such as
peer-review)
fast
cost effective (data is easily produced)
transparent and easy to understand
Why bibliometrics: Citations tracking
Who is citing recognizes the inheritance
received from predecessors.
Why bibliometrics
Citations number becomes an
indicator of paper impact inside a
scientific community
• Find out how many times a paper has been cited
• Search backwards and forwards in time to see how ideas develop
• Find the most highly cited papers in your field
• Identify key researchers and institutions by their citation counts
• See who has influenced particular research
• Identify leading researchers in a particular field
• Identify emerging areas of research
• Identify competitors and potential collaborators
• Assess the impact of an individuals’ or group of individuals’ research output
Why bibliometrics: Citations tracking
Bibliometric : Indicators
Primary
• Number of publications
• Number of citations received
• Number of web page access
• Number of paper downloads
Secondary
• Impact factor
• Immediacy Index
• Cited Half Life
• Citation Index
• H- Index
Bibliometrics Indicators : Impact factor
“...I propose a bibliographic system for science literature that can eliminate the uncritical citation of fraudulent, incomplete, or obsolete data by making it possible for the conscientious scholar to be aware of criticisms”. Garfield E. Citation Indexes for Science. Science 1955 July 15;122(3159):108-111.
1960 Institute for Scientific Information
1964 Science Citation Index
1972 Social Science Citation Index
• “Journal Impact factor” (JIF) is a measurement applied to journals.
• It is based on the citation index database Web of Science.
• It represents the average citation count of the articles published in the
journal.
• The JIF published annually in Journal Citation Reports®.
• The JIF is a journal-level metric designed for one purpose—to
compare the citation impact of one journal with other journals.
Bibliometrics Indicators : Impact factor
Bibliometrics indicators : Impact factor
Impact factor 2010 for « My favourite Journal» =
Number of citations received during 2010 referred to articles published in 2009
and 2008: 20000
------------------------------------------------------------------------
Number of articles published in 2009 and in 2008: 5000
20.000
Impact factor 2010 = 4
5.000
Initiated by the American Society for
Cell Biology (ASCB) together with a
group of editors and publishers of
scholarly journals in december 2012
the need to eliminate the use of journal-based metrics,
such as Journal Impact Factors, in funding, appointment,
and promotion considerations;
the need to assess research on its own merits rather than
on the basis of the journal in which the research is
published;
the need to capitalize on the opportunities provided by
online publication (such as relaxing unnecessary limits on
the number of words, figures, and references in articles,
and exploring new indicators of significance and impact).
Bibliometrics indicators: Impact factor
Bibliometrics where? Journal of citations reports
Compares and evaluates
10,600 journals in
science technology and
social sciences.
Two editions availables
- Science editions
- Social sciences edition
JCR was first produced in 1975 by the
Institute of Scientific Information (ISI),
now Thomson Reuters.
Bibliometrics where? Journal of citations reports
Bibliometrics indicators:Journal of citation reports
• Citing half life
The citing half-life is the median age of
articles cited by the journal in the JCR
year.
• Cited half life
The median age of the articles that were
cited in the JCR year.
It measures the duration of relevance of
articles in a given journal.
• Immediacy index
the average number of times an article is
cited in the year it is published.
It measures how quickly articles in a
given journal have an impact on the
discipline
It could be useful for researchers who
want to publish in a journal from which
they may be quickly cited.
• 5-years journal IF
the average number of times articles
from the journal published in the past
five years have been cited in the JCR
year. Useful because in some fields it
takes longer than two years for citations
to appear.
Bibliometrics indicators: Impact factor
• Easy to calculate
• English centred
• No Transparency
• Citation Window
• Easy to mislead
• Subject differences
• Negative citations
• Citations cartels
H index
Article 1 25
Article 2 20
Article 3 18
Article 4 12
Article 5 10
Article 6 5
Bibliometric indicators: H index
The h-index was created by Jorge Hirsch in 2005.
an h-index of 5 means that
an author (or institution or
journal) has 5 publications
to its name each of which
has been cited at least 5
times.
H index:
It considers both productivity and
impact of a scientist.
It’s very comprehensible
It’s easy to compute
It ignores citations in excess
It doesn’t distinguish the articles
written by a single author from those
written by a group of researchers
it only includes citation to journal
articles (not to books, book chapters,
working papers, reports, conference
papers, etc.);
It penalizes researchers with a short
career
It is discipline dependent
H Index where: databases
Web of Science® is a citation databases hosted by Web of Knowledge
platform
It covers over 12,000 of the highest impact journals worldwide,
including Open Access journals and over 150,000 conference
proceedings.
It has a retrospective coverage in the sciences, social sciences, arts,
and humanities, with coverage to 1900.
Bibliometrics where? Web of Science
H index where:Web of Science
H index where: Web of Science
H index where: Scopus
Scopus is a bibliographic database containing abstracts
and citations for academic journal articles.
It covers nearly 21,000 titles from over 5,000 publishers, of
which 20,000 are peer-reviewed journals in the scientific,
technical, medical, and social sciences (including arts and
humanities).
It is owned by Elsevier and is available by subscription
H index where: Scopus
H index where: Google Scholar
Freely accessible web search engine, part of Google, that
indexes scientific publications from all disciplines, across
the web
www.scholar.google.com
H index where: Google Scholar
• https://addons.mozilla.org/en- US/firefox/addon/77344
http://www.harzing.com/pop.htm
Google Scholar presents the list of publications and citations but can’t calculate
automatically the h index.
Therefore there are a variety of sites and programs “googlescholar- based” and are
generally free.
H index where: Google Scholar
Mycitations profile in Google Scholar
• publication data can be manually edited
• missing publications can be added
• publications can be merged and duplications removed
• It is possible to sign up for notification of new citations to your publications
• New publications will be added automatically to the profile
Web of Science o Subscription required o Advanced citation
searching o Citation data available
from 1990
o Subscription required o Conference papers,
books, chapter, dissertations excluded
o Limited coverage of non English language titles
o Subscription required o Advanced citation
searching and analysis features
o Better coverage of Social Science titles
o Includes conference proceedings
o Subscription required o Books, chapters
dissertations excludeed
o Citation data for papers published from 1996.
o Free o Covers non English
titles o Covers all type of
publications
o No quality control, o Does not cover all
journals o Covers non scholarly
content o Author’s search
H Index where: databases
Source: http://www.ndlr.ie/myri/
Bibliometrics : Eigenfactor
“A measure of the overall value provided
by all of the given articles published in a
journal in a year “
,[
Developed by Jevin West and Carl
Bergstrom - University of Washington
The Eigenfactor™ ranks journals in a manner
similar to that used by Google for ranking the
importance of Web sites in a search
The theory behind Eigenfactor Metrics is that a single
citation from a high-quality journal may hold more value
than multiple citations from more peripheral
publications: a journal is influential if it is cited by other
influential journals.
The Article Influence score for a journal is the journal
Eigenfactor score divided by the number of articles
published by the journal over the five-year target period
References from one article in a journal to another article
from the same journal are removed, :Eigenfactor Scores are
not influenced by journal self-citation
Bibliometrics : SNIP
Created by Professor Henk Moed at CTWS, University of Leiden,
SNIP measures contextual citation impact
by weighting citations based on the total
number of citations in a subject field.
Unlike journal impact factor, SNIP corrects
differences in citation practices between
scientific fields, thereby allowing for more
accurate between-field comparisons
of citation impact.
Uses Scopus data
Source Normalised Impact per Paper
• It measures current average prestige per paper
• It’s freely available on the web
• SCImago website uses journal/citation data from Scopus
• formula: citation time window is 3 years (instead of 2)
• Strong correlation to JIF
Bibliometrics : Scimago Journal Rank
Bibliometrics :Alternative Metrics/Alt-Metrics
Article downloads (from publisher sites)
Article mentions in blogs, media
Articles mentions on Facebook, Twitter
Bookmarks/recommendations made to an article
Bibliometrics :Alternative Metrics/Alt-Metrics
It is essential to keep distinguishing
between scientific scholarly and societal impact
Social media mentions should not be used to measure
the contribution to scientific progress
Bibliometrics :Alternative Metrics
Conclusions
Compare Like with Like
Don’t rely on a single tool
Metrics can improve
research assessement.
No single number is
going to give the
complete picture.
Conclusions
• Gardfield E, Citation Indexes for Science. Science. 1955 Lug 15;122(3159):108-111.
• Garfield E. The History and Meaning of the Journal Impact Factor. JAMA: The Journal of the American
Medical Association. 2006 Gen 4;295(1):90 -93.
• Brubeck. R.A. 2008. Worshiping false idols: the impact factor dilemma. Journal of Child Neurology,
23(4), pp.365-367.
• Ketefian, S. and Freda, M.C. 2009. Impact factors and citation counts: A state of disquiet. International
Journal of Nursing Studies, 46(6), pp.751-752.
• Bar-Ilan J. Informetrics at the beginning of the 21st century--A review. Journal of Informetrics. 2008
Gen;2(1):1-52.
• Bakkalbasi N, Bauer K, Glover J, Wang L. Three options for citation tracking: Google Scholar, Scopus
and Web of Science. Biomed Digit Libr. 2006;3:7.
• Sevinc A. Web of science: a unique method of cited reference searching. J Natl Med Assoc.
2004Lug;96(7):980-983.
• Falagas ME, Pitsouni EI, Malietzis GA, Pappas G. Comparison of PubMed, Scopus, Web of Science, and
Google Scholar: strengths and weaknesses. FASEB J. 2008 Feb;22(2):338-342.
• Kulkarni AV, Aziz B, Shams I, Busse JW. Comparisons of citations in Web of Science, Scopus, and
Google Scholar for articles published in general medical journals. JAMA. 2009 Set 9;302(10):1092-
1096.
• Seglen PO,Why the impact factor of journals should not be used for evaluating research BMJ. 1997 Feb
15;314(7079):498-502.
Basic Bibliography
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