Transcript Irma Pasanen

Journal Impact Factors
and
Other Bibliometric Indicators
Irma Pasanen
Aalto University Library
7.5.2010
Visibility and Impact
• Visibility
– Publication visibility in international databases and search
engines
– Open Access
• Impact
– Citations received
… in the light of the source data and
according to its categorization…
The coverage of the source data
 Scientific disciplines are different in their communication
• in doing research (group work or solitary assignments)
• in reporting research (publishing channels, writing
conventions)
• in the use of references (citations)
The accuracy and classification of the source data
Bibliometrics
Bibliometrics is looking at publishing
using quantitive (statistical and
mathematical ) methodologies
•
•
•
Pareto principle
Bradford´s law of scattering
Garfield´s law of concentration
ISI, Scopus and Google Scholar
• ISI Thomson Reuters (ISI Web of Science)
• Scopus (Elsevier) 2004 –
(access through Nell portal)
• Google Scholar (beta) ~2005 –
(http://scholar.google.com)
Discipline-based, e.g.
• CiteSeer (primarily computer and information science)
http://citeseerx.ist.psu.edu/
ISI Web of Science
ISI Web of Science databases Number of
indexed
journals
Science Citation Index
5900
Social Science Citation Index 1700
Arts and Humanities Citation 1130
Index
ISI Journal Citation Reports (JCR)
IMPACT FACTOR
number of citations received in current year by papers
published in the journal in the previous two (or five)
years
divided by
number of papers published in the journal in the
previous two (or five) years
Note: high impacct factor does not equal high quality or
superior scientific value
ISI Journal Citation Reports (JCR)
Scopus
Scopus
4 Subject fields
Number
of
indexed
journals
•Health Sciences
•Life Sciences
•Physical
Sciences
•Social Sciences
(incl. Arts and
Humanities)
5300
3400
5500
2850
Scopus
SJR SCImago Journal Rank
- Is weighted by the prestige of the journal, thereby
‘leveling the playing field’ among journals
- Eliminates manipulation: raise the SJR ranking by
being published in more reputable journals
- ‘Shares’ a journal’s prestige equally over the total
number of citations in that journal
- Normalizes for differences in citation behavior
between subject fields
SNIP Source Normalized Impact per Paper
- Measures contextual citation impact by
‘normalizing’ citation values
- Takes a research field’s citation frequency into
account
- Considers immediacy - how quickly a paper is likely
to have an impact in a given field
- Accounts for how well the field is covered by the
underlying database
- Calculates without use of a journal’s subject
classification to avoid delimitation
- Counters any potential for editorial manipulation
Applications with ISI and Scopus journal
data
Ranking and Mapping Scientific
Knowledge http://www.eigenfactor.org/
• Data from ISI Web of Science
SCImago Journal and Country Rank
http://www.scimagojr.com
• Data from Scopus
Hirsch Index
A scientist has index h if h of his
Np papers have at least h
citations each, and the other
(Nph) papers have no more
than h citations each.
• Hirsch index can be used to
compare scientists within the
same field, but not across
disciplines. It can be a useful
http://en.wikipedia.org/wiki/Hirsch_number
indicator among scientists who
have already published a good
number of publications.
Playing the game
•
•
•
•
•
Name(s) and initials
Affiliation(s)
Co-authors
Self-citations
ResearcherID
AaltoRAE
ISI vs. Scopus
Source data matters, however:
the importance of journals in
the scholarly communication
varies.
Results of a study in ISI databases
showed that e.g. in
- Chemistry 91 %
- Electron. & electrical engineering
65 %
- Robotics 49 %
of references were made to
documents published in
journals
Aalto RAE bibliometric analysis
Indicators:
1.
Number of papers
2.
Number of fractionalized papers
3.
Citations per paper
4.
Citations per paper with a 2-year citation window
5.
Journal normalized citation score
6.
Normalized journal citation score
7.
Field normalized citation score (Crown Indicator)
8.
Standard field citation score
9.
Percentage of papers above the 95th citation percentile
10. Vitality (recency of references)
11. Percentage of self-citations
12. Percentage of not cited papers during the period
13. Mean number of countries per paper
14. Mean number of authors per paper
15. H-index
www.aalto.fi/aaltorae
Questions?
Thank you !