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

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

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

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

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

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

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.

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 ->

(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

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

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

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

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

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.

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 …

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 ?

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!

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.

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

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

Reports 3 measures

Impact factor

Immediacy Index

Cited half life

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”

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

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 .

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?

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

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

A.G.J. Voragen or A. Voragen or F. Voragen or F.A.G.J. Voragen or F.G.J. Voragen