Citation analysis for research evaluation

Citation analysis for research evaluation Wouter Gerritsma, Marc Loman, Marianne Renkema Information Specialists, Wageningen UR Library

Programme
Introduction
Citation data
Benchmarking
Journal quality
Ranking University
On publishing

Why research evaluation/citation analysis?
Research assement of graduate schools (5 year cycle, stipulated by the VSNU)
Other research groups are reviewed in a similar way
Benchmarking becomes more important
Grant applications
Job positions
In the press
Sooner of later, you will be subjected to such an analysis

Objective of this course
How are citation analyses performed, and what are their shortcomings or weaknesses?
What can you do to enhance your results

Citation data

Citation data
Paid subscription (wide coverage)
Web of Science
Scopus
Free systems broad coverage
Google Scholar
Paid subscription (specialized coverage)
SciFinder
Psychindex
Free systems (specialized coverage)
Citeseer
Citebase

Web of Science
Thomson Scientific
Founder Eugene Garfield
Formerly: Institute of Scientific Information (ISI)
Indexes articles of about 8700 journals, standard bibliographic information + reference lists
Sell the same data in various databases to libraries and others (CC, WoS, JCR, ESI)
They (still) have monopoly position for citation data; they are the Golden Standard

CC, WoS, JCR, ESI
CC: Current Contents, weekly updated bibliographic database covering the top of Sciences (no citation data)
WoS: Web of Science, weekly updated database, that includes references and citation data as well (slower than CC)
JCR: Journal Citation Report, yearly analysis of WoS data, presenting perfomance measures for journals.
ESI, Essential Science Indicators, bimonthly updated analytical database giving performance measures for Countries, Institutes, Scientists and Journals next to research fronts, hot papers and baselines.

Database Coverage WoS/JCR/CC Source: Moed (2005) Mathematics / Engineering / Economics Other social sciences related to medicine & health Physics & Astronomy Psychology & psychiatry Clinical medicine Humanities Biological Sciences related to plants & animals Biological Sciences related to humans Other Social Sciences Applied physics & Chemistry Molecular biology & Biochemistry Moderate Good Excellent

Scopus
(New) product of Elsevier Science
Covers 15,000 serials
Not all of them peer reviewed
Coverage of citation data 1996 ->

Google Scholar
Free database
Some concerns about data quality
Unknown source base
Very labour intensive to extract data

Why Scopus doesn't add substantially to the number of citations found in WoS Source: http://www.wowter.nl/blog/2007/01/why-scopus-doesnt-add-substantially-to.html

Searching WoS
General search: Searches bibliographic data: Title, Abstract, keywords, Authors, Addresses
Not all citations are found due to errors in citing, indexing etc.
Cited reference search: searches in the references of source data
Not all articles are found. Non cited articles are missing

Exercises !

Benchmarking

Benchmarking
Essential Science Indicators (ESI)
h-index

How do we compare numbers?
Scientist Z. Math has a publication from 1996 with 17 citations
Scientist M. Biology has a publication from 2003 with 24 citations

Baseline mathematics

Baseline Molecular Biology

Essential Science Indicators (ESI)
Analytical database of SCI, covering 10 years + current year building
Comparison between Countries, Institutes, Scientists and Journals
Hot papers / Highly cited papers
Research fronts
Baselines

Publication age : world averages citations (1)

In practice

Relative impact of a research institute 1,84 2,26 2,08 2,06 All subfields 1,73 0.57 1,70 Microbiology 1,11 1,81 1,73 Clinical medicine 1,76 1,76 Chemistry 1,09 0,44 1,55 0,91 Biology & biochemistry 3,60 3,87 3,86 3,82 Agricultural Sciences Group 3 Group 2 Group 1 All groups Subfield

Evaluation of candidates 0 3 0,83 0,58 0,75 346 57 e 3 16 1,94 1,69 1,86 1886 88 d 0 8 0,9 1,39 1,15 972 93 c 1 17 1,95 1,84 1,93 498 65 b 2 4 1,52 1,76 1,64 1565 80 a #papers top 1% #papers top 10% RI 1999-2003 RI 1994-1998 Relatieve Impact #Citations # Papers 1994-2003 Author

h-index
A scientist has index h if h of his/her Np papers have at least h citations each, and the other (Np − h) paper have no more than h citations each.

h-index
h-index tries to find a balance between productivity and citation impact
Only published in 2005, has made a substantial impact in the world of bibliometrics.
Implemented in Spires, WoS (and soon) in Scopus
Applicable to authors, journals, research groups, compounds, subjects etc …

Exercises !

Journal quality

Journal quality
JCR (Impact factors)
ESI
h-index
Or pagerank ?

Warning !
It has often been attempted to use Journal Impact factors in some or other way to judge the performance of a group or individual scientists.
This is proven very bad practice!

Impact factor
Performance measure for journals
“… it is also used for assessment of the quality of individual papers, scientists and departments. For the latter a scientific basis is lacking, as we will demonstrate in this contribution” (Opthof, 1997)
Opthof, T. (1997). Sense and nonsense about the impact factor. Cardiovascular Research 33 (1): 1-7. http:// dx.doi.org /10.1016/S0008-6363(96)00215-5

Journal Citation Reports (JCR)
Reports 3 measures
Impact factor
Immediacy Index
Cited half life
Cited half-life 50% citations 50% citations 3 1 Immediacy index Window Impact Factor Window

Definition of Impact factor
The impact factor of a journal J in year T is defined as follows:
“ The number of citations received in year T by all documents published in J in the years T-1 and T-2”
÷
“ The number of citable documents published in J in the years T-1 and T-2”

Citable items
Cited items (nominator) include:
Research articles, review arrrticles, notes, letters, editorials, news items, corrections and meeting abstracts
Citable items (by definition)
Articles, notes and reviews

Lancet (2002) JCR Like IF = (b)/(a) = 10.2 2.4 15,670(b) 6,443 Total 0.5 2,564 4,899 Other types 8.5 13,106 1,544 (a) Articles/reviews (citable items) Cites/Doc Cites No. Docs Type of document

50 % of articles generate 90% of all cites Seglen, P. O. (1997). Why the impact factor of journals should not be used for evaluating research. BMJ 314 (7079): 497-502. http://bmj.bmjjournals.com/cgi/content/full/314/7079/497

Some other points
IF measures citation impact of articles in 2 nd & 3 rd year after publication. Therefore biased towards journals showing rapid maturing.
Reference practices, particularly the number of references per article and their age distribution, vary considerably among subfields. IF between subfields can not be compared .

When do you make use of IF
Answering the questions where do you want to publish your manuscript.
Other questions, to be asked
Reach colleagues ?
In which article indexes included?
Open access?

Exercises !

Ranking universities
Popular lists
Shanghai Jiao Tong University
THES
Newsweek
ISIhighly cited
ESI
Other reports
EC, NOWT, OECD, USA

Winding down

What’s in a name?
A.G.J. Voragen or A. Voragen or F. Voragen or F.A.G.J. Voragen or F.G.J. Voragen

http://www.wowter.nl	23
http://www.slideshare.net	23

Citation analysis for research evaluation

by Wouter Gerritsma

Accessibility

Categories

Upload Details

Usage Rights

2 Embeds 46

Statistics

Citation analysis for research evaluation Presentation Transcript