آشنايی با مبانی و کارگاه -Hشاخص های علم سنجی:

Indexو محاسبه آن

برگزار کننده گان:وزارت معاونت تحقيقات و فن آوری

با بهداشت، درمان و آموزش پزشکی، همکاری دانشگاه علوم پزشکی تهران

آشنايی با مبانی و شاخص های علم سنجی:

H-Indexو محاسبه آن

Payam Kabiri, MD. PhD.Epidemiologist

Tehran & IsfahanUniversities of Medical Sciences

! برنامه امروز

اطالع سنجی و علم سنجی، مفاهيم و کاربردمعرفی خالصه شاخص های علم سنجیآشنايی با نمايه نامه های استنادی معرفی شاخصH-Index مزايا و معايبH-Index روش های محاسبه H-Indexکار عملی

Scientometrics (bibliometrics)

Scientometrics (bibliometrics) - The measurement of scientific output activity through statistics on academic publications

• The scope of bibliometrics includes:

“all quantitative aspects and models of science communication, storage, dissemination and retrieval of scientific information”.

سنجی تعريف علم

ی را که به تحليلNآن دسته از روش های کمعلم بعنوان يک فرآيند اطالعاتی تأکيد دارند

”علم سنجی“ می نامند. علم سنجی“ به تعبيری ساده تر عبارت”

گير علم. است از دانش اندازه

Scientometrics

informetrics

bibliometrics

scientometrics

webometrics

cybermetrics

Bibliometric data used for..

Scientific output evaluation Impact Citations

History of science Publication strategies Science policy; resource allocation Collection management Sociology of science Information organization Information management & utilization

Webometrics

Informetrics

Mathematics/Physics

Library andInformation Science

Sociology of science

History of science

Economics

Scientific information

Services for

Research in

Librarianship

Science policyResearch management

Scientometricsapplied

basicLife sciences

Links of bibliometrics with related research fields and application services

International

National

Institutional

Faculty

Researchers

• Grant Allocations• Policy Decisions• Benchmarking• Promotion• Collection management• Funding allocations• Research

Why do we evaluate scientific output

SPLIT IN NEEDS

SPLIT IN NEEDS

Scientists Ranking Methods

Evaluation of scientists by “experts” e.g., surveys

Citation Analysis Task: Compute a score for the “objects”

Hybrid method of previous two

3 Kinds of Citation Data Indexes

Articles Citation Impact

Authors Number of papers (Quantity) Number of Citations (Quality) Average number of citations/article h-index & g-index (Quantity & Quality Both)

Journals Journal Impact Factor h-index

A Sample of a Sceintometery Report

3 Kinds of Citation Data

Articles Citation Impact

Authors Number of papers (Quantity) Number of Citations (Quality) Average number of citations/article h-index & g-index Quantity & Quality Both)

Journals Journal Impact Factor h-index

ISI Impact FactorA= total cites in 1992 B= 1992 cites to articles published in 1990-91 (this is a subset of A)*

C= number of articles published in 1990-91D= B/C = 1992 impact factor

Citation Databases

Web of Science Scopus Google Scholar

Other Tools Available

Other bibliometric indicators: Journal Citation Reports (JCR) Other indicators databases (national,

essential, university, institutional) ISIHighlyCited.com

Science, 77

Social Sciences, 14

Arts & Humanities,

9

WoS and Scopus: Subject Coverage (% of total records)

WoS SCOPUS

Google Scholar ?

Biological & Environmental Sciences, 13

Social Sciences, 2

Physical Sciences, 25

Health & Life Sciences, 60

Web of Science

Covers around 9,000 journal titles and 200 book series divided between SCI, SSCI and A&HCI.

Electronic back files available to 1900 for SCI and mid- 50s for SSCI and mid-70s for A&HCI.

Very good coverage of sciences; patchy on “softer” sciences, social sciences and arts and humanities.

US and English-language biased. Full coverage of citations. Name disambiguation tool. Limited downloading options.

Scopus

Positioning itself as an alternative to ISI More journals from smaller publishers and open access

(+15,000 journals; 750 conf proceedings) Source data back to 1960. Excellent for physical and biological sciences; poor for social

sciences; does not cover humanities or arts. Better international coverage (60% of titles are non-US) Back to 1996 ! (e.g. citation data for the last decade only) Not “cover to cover” and not up to date Easy to use in searching for source publications; clumsy in

searching cited publications. Citation tracker works up to 1000 records only. Limited downloading options.

Google Scholar

Better coverage for all citations as it retrieve web ! More coverage of references also gray literature ! Coverage and scope? Inclusion criteria? Very limited search options No separate cited author search Back to 1990 NOT more ! Free!

What is Scopus Database?

Scopus (Databaseمعرفي بانک اطالعاتي   ) عنوان مجله15200پوشش اطالعاتي بيش از از بيش از 30دربرگيرنnده مقالnه خالصnه ميليnون

ناشر بزرگ بين المللي4000 ميليون 265 دربرگيرنده بيش از Citation تمامي مجالت نمايه شده در مدالين دربرگيرنده

23

What is Scopus?

+15,200 titles from more than 4,000 publishers +1,000+ Open Access journals +500 Conference Proceedings 400M web pages 21M patents Repositories Digital Archives

WebsitesWebsitesand digital and digital archivesarchives

Peer Peer reviewedreviewed

literatureliterature

ScienceScienceMedicineMedicineTechnologyTechnologySocial sciencesSocial sciences

PatentsPatents

Institutional Institutional repositoriesrepositories

Content Update

30 million records, of which: 15 million records include references going back to 1996 15 million pre-1996 records go back as far as 1900

265 million references, added to records from 1996 onwards In addition to traditional scientific and academic journals, Scopus covers:

1000 Open Access journals 500 Conference Proceedings 600 Trade Publications 125 Book Series Medline (100% coverage) 275 million quality web sites including 21 million patents from 5

patent offices UK Patents added to Scirus

25

Focused web

information

Academic library

sources

15,100 titles

4,000 publishers

STM & Social sciences

World’s Largest

Abstract & Citation

Database

What is Scopus?

15% Elsevier sources

85% other publishers

240 million scholarlyWeb items, E-prints, theses, dissertations, 13 M patents

Fastest route to FullText

Abstract from 1966

Abstract + references 2006/1996

15,100 current journal sources

1966

2006

1996

Abstract30 million

+1.1 million per year

Cited References

265 million10 years

+ 25 million each year

Currency

Updated daily

Valuable archive included

2,7002,7002,5002,5004,5004,5005,9005,900

Life & Health(100% Medline(

ChemistryPhysics

Engineering

BiologicalAgriculturalEnvironment

al

Social Sciences

PsychologyEconomics

Scopus Coverage15,100 Unique titles

28

5336

198

6872

189

806

1390

251

International distribution of titles

29

Geographical spread of Scopus content

˼̌6

˼̌8̂9̂ ˻

North America

South America

Asia Pacific

Europe, Middle East & Africa

30

Iranian Titles indexed in Scopus

• Iranian Biomedical Journal

• Archives of Iranian Medicine

• Daru

• Iranian Journal of Diabetes and Lipid Disorders

• Iranian Journal of Medical Sciences

• Iranian Journal of Public Health

• Journal of Medicinal Plants

• Yakhteh

Bibliometric Tool Development of Scopus

2005 20062004 2007

Launch Scopus

• Citation Tracker• Author Identifier• WebCites• PatentCites

• h-index• Custom Data

* End 2007 release

Scopus for science evaluation

Literature Search

Market Feedback & Development

Introducing RPM tools

IMPLEMENT

STRATEGY

Difficulties of Old Criteria

Total number of papers (Quantity) Total number of citations (Quality) Average number of citations/article

(Deepened on the outliers) Journal Impact Factor (Discipline based,

dependent on the outliers)

H-index was born !

We need an Index both to include quantity & also quality of an authors' paper Productivity Impact

Not affected by “big hits” Not affected by “noise”

Hirsch, J. E. (2005). An index to quantify an individual's scientific research output. Proceedings of the National Academy of Sciences of the United States of America, 102(46), 16569-16572.

Meaningful when compared to others within the same discipline area. Researchers in one field may have very different h-indices than researchers in another (e.g. Life Sciences vs. Physics).

The h-index

Hirsch, J.E. "an index to quantify an individual's scientific research output". Proceedings of the National Academy of Sciences of the United States of America (PNAS). 102(46), 16569-16572

Available at: http://arxiv.org/pdf/physics/0508025

The h-index

The H-index: a definition

‘The H-index is the highest number of papers a scientist has that have at least that number of citations.’ Nature (2005)

What is the h-Index?

Performance measurement tool for scientific authors (similar idea to journal impact factors but for individuals)Established by Jorge Hirsch at UC San Diego

“A scientist has index h if h of his/her Np papers have

at least h citations each, and the other (Np- h) papers

have no more than h citations each.”

Source: Hirsch, J. E. (2005, September 29). An index to quantify an individual’s scientific research output. Retrieved from http://arxiv.org/abs/physics/0508025

Definition:A researcher has h-index h if h of his Np articles have received at least h

citations each the rest Np-h articles have received no more than

h citations each

The h-index

H-index Concept through its Graph

The h - Graph

ت. اينnنجي اسnاخص هاي علم سnدي از شnشاخص جدي Jorge Hirsch ميالدي توسط 2005شاخص در سال

در دانشnگاه کاليفرنيnا ابnداع شnد. اين شnاخص در واقnع بnا هnدف ارزيnابي کيفي اثnر و ارزيnابي کمي بnرون داد

پژوهشي محققين ابداع شده است.

The h-index

ومnمفهH-Index هnنده کnاالت نويسnداد مقnت از تعnارت اسnعب nاnب ارجnاعnاتn nبرابnر nدnداnعnتh مثالn .دnرنnدا آnن کnمnتر nاز يnا و

nهnچنان چ H-Index يnت 5محققnاس nوم آن اينnد، مفهnباش دارnد nکnه nهرکnداnم 5کnه nاين nمحقnق شnده مnنتشnر مnقالnه

دارنnد. بnه عnبnارت nديگnر مفهnوم n Citationnاسnتناد يnا 5حnدnاقل n nاز nترnمnک محقnق اnين سnايرn nمقnاالت کnه اnسnت 5آن nاnين

استناد دارند. امروزه اين شاخص معادل Impact Factor براي محققين

محسوب مي شود.

The h-index

اخصnترين شnبزرگh وزهnه حnوط بnا مربnدر دني بnا برابnر زيسnتی بزرگnترين 197علnوم و

دکnتر hشnاخص آقnای جنnاب ايnران محققnان رازی دانشnگاه شnيمی اسnتاد پnور شمسnی

می باشد.33برابر hکرمانشاه با عدد

The highest h-index in the World & Iran

Terminology

Np: total number of papers

Nc,tot: total number of citations

Y(now): present year Y(i): year of publication of paper i C(i): set of citations to paper i

The h-index

A scientist has index h if h of his or her Np papers have at least h citations each and the other ( Np – h ) have at least ≤ h citations each

Doc 1 2 3 4 5 6 7 8 9 10 11

Cit 49 23 15 14 6 3 1 1 0 0 0

46

Author A

Author B

Doc 1 2 3 4 5 6 7 8 9

Cit 55 45 20 10 5 4 3 2 1

Doc 1 2 3 4

Cit 25 20 9 6

H-index example

H-index example

Author X has 5 published articles:Article1, citations 5Article2, citations 10Article3, citations 100Article4, citations 6Article5, citations 4

The H-index of X is 4: there are 4 papers with at least 4 citations each.

It could be used for an specific Author: Evaluate the Research Performance of Author

Or could be used for a group of Papers of an institution, department or journal which Evaluate the Impact of the group of special

papers

The h-index

H-index drawbacks

Like impact factors depends on subject area It is a growing function over time It does NOT show the current activity or

inactivity of the author Disadvantages younger researchers (without

previous track record) Scientists with short scientific life are out of

competition

The Contemporary h-index

The Contemporary h-index was proposed by Antonis Sidiropoulos, Dimitrios Katsaros, and Yannis Manolopoulos

It adds an age-related weighting to each cited article, giving less weight to older articles.

The g-index

The g-index was proposed by Leo Egghe It is defined as follows:

[Given a set of articles] ranked in decreasing order of the number of citations that they received, the g-index is the (unique) largest number such that the top g articles received (together) at least g2 citations.

It aims to improve on the h-index by giving more weight to highly-cited articles.

The g-index

Suggested in 2006 by Leo Egghe. The index is calculated based on the

distribution of citations received by a given researcher's publications.

The g-index

Given a set of articles ranked in decreasing order of the number of citations that they received, the g-index is the (unique) largest number such that the top g articles received (together) at least g2 citations

This index is very similar to the h-index, and attempts to address its shortcomings.

The h-b-index

The h-b-index developed by Michael Banks of the Max Planck Institute for Solid State Research in Germany, takes the index further by evaluating the impact of compounds used in solid-state physics and scientific topics in general.

The h-b-index is defined in the same manner as the h-index, but is based on a topic (or compound) search instead of a scientists name.

The h-b-index

A scientist has index h if h of his/her Np papers have at least h citations each, and the other (Np – h) papers have at most h citations each.

For the case of a topic it is useful to define the h-b index in terms of the number of years, n as h = nm

If the h-b index is linear with the number of years, then m is given as the gradient. In this respect, a compound or topic with a large m and h-b index can be defined as a hot topic.

The H-Graphs in Scopus

A more comprehensive way evaluating an author Using Author Search, Scopus give us three different graphs

H-Index Graph of given Author No of Author Papers (Articles) per year No of Author Citations per year

57

No of articles

h-index plot

No of citations

58

The h-index

Plots citations per article Incision = h-index Shows low & highly

cited-by counts Completely transparent The date range can change

Practical Interpretation:Promotion, Evaluation, Funding, Tenure, Benchmarking

59

Author articles history

Shows level of activity

Shows peaks and troths in publication history

Can change the date range

Practical Interpretation:Promotion, Evaluation, Funding, Tenure, Benchmarking

60

Author Cited-by’s

Shows level of activity Shows highs & lows Can change the date

range Time lag!

Practical Interpretation:Promotion, Evaluation, Funding, Tenure, Benchmarking

How to calculate h-index through Scopus

There is two way to calculate it according to the way you want:

If you want it for an Author: Search the Author, It will calculate it

Automatically for you.

If you want it for a group of Papers Search them & then use the track citation & sort

them out to count & calculate it Manually.

62

The Hirsch Index:For a Group of Papers

Run an author search

Sort result by citations, clicking on Cited by

Scroll down the new display of results until the ranking number is equal or less than the number of citations.

That ranking number is the Hirsch Index for that author.

Author Identifier functionality

• Author Identifier enables Scopus users to avoid two major problems which affect most A&I databases:

How to distinguish between an author’s articles and those of another author sharing the same name?

How to group an author’s articles together when his or her name has been recorded in different ways?

• With other databases, these problems can result in retrieving incomplete or inaccurate results.

Calculating the H-index:For a Group of Papers

Indicators of quality as measured using published outputs

Number of publications Citation counts to these publications (adjusted for self-citations) -what

“window” should be used? 4, 5, 10 years? Citations per publication Percentage of uncited papers Impact factors (of publishing journals) Diffusion factor (of citing journals) – profile of users of research

(who, where, when and what) “Impact factor” of a scholar - Hirsh index (h index)

(numbers of papers with this number of citations). Your h index =75 if you wrote at least 75 papers with 75 citations each.

Note: These should not be seen as “absolute” numbers but always seen in the context of the discipline, research type, institution profile, seniority of a researcher, etc.

Calculating h-index using Thomson ISI Web of Science

1) Conduct a General Search2) Automatic: click on “Citation

Report”, or,3) Manual: sort by “Times Cited”

Calculating h-index using Google Scholar

There are different ways to do it & also different interfaces: 1- Publish or Perish InterfaceYou can download it here.2- Another Script, Click here.3- Also this one.

Compare like with like!

Applied research attracts fewer citations than basic research. Differences in citation behaviour between disciplines (e.g. papers in

organisational behaviour attract 5 times as many citations as papers in accounting).

Highest IF journal in immunology is Ann Rev Immun (IF 47.3) Mean for cat. 4.02; and in health care and services category is Milbank Q. (IF of 3.8). Mean for cat. 1.09.

Matthew effect.Benchmarking must be done using comparable variables!

Harzing’s Publish or Perish

A software program that retrieves and analyzes academic citations. It uses Google Scholar to obtain the raw citations, then analyzes these and calculates a series of citation metrics.

H-Index Advantages

The h-index was intended to address the main disadvantages of other bibliometric indicators, such as total number of papers or total number of citations.

It simultaneously measure the quality and sustainability of scientific output, as well as, to some extent, the diversity of scientific research.

H-Index Advantages

The h-index is much less affected by methodological papers proposing successful new techniques, methods or approximations, which can be extremely highly cited. For example, one of the most cited condensed matter theorists, John P. Perdew, has been very successful in devising new approximations within the widely used density functional theory. He has published 3 papers cited more than 5000 times and 2 cited more than 4000 times. Several thousand papers utilizing the density functional theory are published every year, most of them citing at least one paper of J.P. Perdew. His total citation index is close to 39 000, while his h-index is large, 51, but not unique. In contrast, the condensed-matter theorist with the highest h-index (94), Marvin L. Cohen, has a lower citation index of 35 000. One can argue that in this case the h-index reflects the broader impact of Cohen's paper in solid-state physics due to his larger number of highly-cited papers.

The h-index is bounded by the total number of publications. This means that scientists with a short career are at an inherent disadvantage, regardless of the importance of their discoveries. For example, Évariste Galois' h-index is 2, and will remain so forever. Had Albert Einstein died in early 1906, his h-index would be stuck at 4 or 5, despite his being widely acknowledged as one of the most important physicists, even considering only his publications to that date.

The h-index does not consider the context of citations. For example, citations in a paper are often made simply to flesh-out an introduction, otherwise having no other significance to the work. h also does not resolve other contextual instances: citations made in a negative context and citations made to fraudulent or retracted work. (This is true for other metrics using citations, not just for the h-index.)

The h-index does not account for confounding factors. These include the practice of "gratuitous authorship", which is still common in some research cultures, the so-called Matthew effect, and the favorable citation bias associated with review articles.

H-Index Problems

The h-index has been found to have slightly less predictive accuracy and precision than the simpler measure of mean citations per paper.

While the h-index de-emphasizes singular successful publications in favor of sustained productivity, it may do so too strongly. Two scientists may have the same h-index, say, h = 30, but one has 20 papers that have been cited more than 1000 times and the other has none. Clearly scientific output of the former is more valuable.

H-Index Problems

The h-index is affected by limitations in citation data bases. Some automated searching processes find citations to papers going back many years, while others find only recent papers or citations. This issue is less important for those whose publication record started after automated indexing began around 1990. Citation data bases contain some citations that are not quite correct and therefore will not properly match to the correct paper or author.

The h-index does not account for the number of authors of a paper. If the impact of a paper is the number of citations it receives, it might be logical to divide that impact by the number of authors involved. (Some authors will have contributed more than others, but in the absence of information on contributions, the simplest assumption is to divide credit equally.) Not taking into account the number of authors could allow gaming the h-index and other similar indices: for example, two equally capable researchers could agree to share authorship on all their papers, thus increasing each of their h-indices. Even in the absence of such explicit gaming, the h-index and similar indices tend to favor fields with larger groups, e.g. experimental over theoretical.

H-Index Problems

Edward WittenPhysicisth=132

Stephen HawkingPhysicist

h=62

But more people know who I am!

My h-index is bigger than yours!

اگر میل داشتید Email ! بزنید

payam.kabiri@gmail.com