An introduction to traditional bibliometrics and the use of some newer tools for measuring scholarly influence and impact.

1. Bibliometrics :
Essential Concepts and Tools
Elaine M. Lasda Bergman
Bibliographer for Social Welfare
and Dewey Reference
Dewey Graduate Library

2. What is bibliometrics?
Scholarly communication: tracing the history and
evolution of ideas from one scholar to another
Measures the scholarly influence of
articles, journals, scholars

3. The birth of citation analysis
Eugene Garfield: “father of citation analysis”
developed the first bibliometric index tools
Citation indexes and Journal Citation Reports
“ISI Indexes”: Science Citation Index, Social Science
Citation Index, Arts and Humanities Index
Better coverage on hard sciences than on social
sciences and worse still on humanities

4. Garfield’s metrics
Citation count
Impact Factor
Immediacy Index
Citation Half-Life

5. Citation count
Number of times cited within a given time period
Author
Journal
Does not take into account
Materials not included in citation database
Self citations

6. Impact factor
Measures “impact” of a journal (not an article) within
a given subject
Formula is a ratio:
Number of citations to a journal in a given year from
articles occurring in the past 2 years Divided by the
number of scholarly articles published in the journal in
the past 2 years

7. Concerns with impact factor
Cannot be used to compare cross disciplinary (per
Garfield himself) due to different rates of publication
and citation
Two year time frame not adequate for non-scientific
disciplines
Coverage of some disciplines not sufficient in the ISI
databases
Is a measure of “impact” a measure of “quality”?

8. Immediacy index
What it’s supposed to measure: how quickly articles in
a given journal have an impact on the discipline
Formula: the average number of times an article in a
journal in a given year was cited in that same year

9. Citation Half-Life
What it’s supposed to measure: duration of relevance
of articles in a given journal
Formula: median age of articles cited for a particular
journal in a given year

10. Twenty first century tools

11. Influence of Google Page Rank
Eigenvector analysis:
“The probability that a researcher, in documenting his or
her research, goes from a journal to another selecting a
random reference in a research article of the first
journal. Values obtained after the whole process
represent a ‘random research walk’ that starts from a
random journal to end in another after following an
infinite process of selecting random references in
research articles. A random jump factor is added to
represent the probability that the researcher chooses a
journal by means other than following the references of
research articles.” (Gonzales-Pereira, et.al., 2010)

12. Sources Using ISI Data

13. Journalranking.com
Journal Ranking.com uses ISI data and eigenvector
(PageRank) algorhythm to create one’s own
categories
Can assign different weights to citations from the same
journal, the same category and from other categories or
only whithin a specific list
Not updated since 2005
http://libguides.library.albany.edu/content.php?pid=600
86&sid=441804

14. Eigenfactor.org http://libguides.library.albany.edu/content.php?pid=60086&sid=441804
Uses ISI data
Similar to PageRank
Listed in JCR as of 2009
Eigenfactor Score :
Influence of the citing journal divided by the total
number of citations appearing in that journal
Example: Neurology (2006): score of .204 = an estimated
0.2% of all citation traffic of journals in JCR (Bergstrom &
West, 2008).
Larger journals will have more citations and therefore will
have larger eigenfactors

15. Article Influence Score
From Eigenfactor: measure of prestige of a journal
Average influence, per article of the papers on a
journal
Comparable to the Impact Factor
Corrects for the issues of journal size in the raw
Eigenfactor score
Neurology’s 2006 article influence score = 2.01. Or
that an avg. article in Neurology is 2X as influential as
an avg. article in all of JCR

16. ScienceWatch
Provides “quick and dirty” articles on hot
researchers, trending research topics, institutions and
journals
Much on this site (in-cites, etc) are now parts of
analytical products being sold byThompson; no longer
free
There are still some good articles, but not
searchable, hit or miss information
http://sciencewatch.com/dr/sci/11/

17. New sources for citation information
Google Scholar
Scopus

18. Scopus:
alternate database of citation data
Review panel, i.e., quality control
Bigger field than ISI: covers all the journals in WoS and
more
Strongest in “hard”sciences”, ostensibly improved
social science coverage, arts and humanities: are
“getting there”
Algorithmically determined with human editing

19. Google Scholar
alternate database of citation data
No rhyme or reason to what is included
Biggest source of citation data
Foreign language sources
Sources other than scholarly journals
Entirely algorithmically determined, no human editing

20. Scopus analytics
SNIP
SJR/SCIMago
Author Evaluator

21. SNIP
(Source Normalized Impact Per Paper)
Journal Ranking based on citation analysis with
adjustments for the frequency of citations of the
other journals within the field (the field is all journals
citing this particular journal)
SNIP is defined as the ratio of the journal’s citation
count per paper and the citation potential in its
subject field. (Moed, 2009)
http://www.scopus.com/home.url

22. SJR:SCImago Journal Rank
What it’s supposed to measure: “current “average
prestige per paper”
SCImago website uses journal/citation data from
Scopus, and is also available from scopus db
Formula: citation time window is 3 years instead of 2
like JIF
Corrections for self citations
Strong correlation to JIF

23. SCImago Journal Rank
Prestige factors include: number of journals in
db, number of papers from journal in
database, citation numbers and “importance”
received from other journals: size dependent: larger
journals have greater prestige values
Normalized by the number of significant works
published by the journal: helps correct for size
variations
Corrections made for journal self citations

24. Scopus Author Evaluator
Breakdown of documents by source
H-index
Citations per year (graph)

25. Google Scholar
Publish or Perish
CIDS

26. Publish or Perish
Provides a variety of metrics for measuring
scholarly impact and output.
More useful for metrics on authors than journals
or institutions
Uses Google Scholar citation information
Useful for interdisciplinary topics, fields relying
heavily on conference papers or reports, non-
English language sources, new journals, etc.
Continuously updated since 2006

27. Publish or Perish Metrics
Basic metrics:
# papers, #citations, active years, years since first
published, average #of citations per paper, average # of
citations per year, average # citations per author, etc.
Complex metrics
H index (and its many variations, mquotient, g-index (corrects
h-index for variations in citation patterns), AR index, AW
index
Does not have any corrections for SELF
CITATIONS

28. CIDS
Measures output of authors for prestige and
influence
Similar to PoP
Corrects for Self-Citations
Uses Google Scholar data

29. CIDS metrics
Citations per year, h-index, g-index, total
citations, avg cites per paper, self citations included
and excluded, etc.
http://cids.di.fc.ul.pt/cids_3_0/info.php?acc=252015140
41114103161

30. Mesur
Metric based on usage, citation and bibliographic
data
Uses its own datbases of
documents/metadata/reference, users &
authors, “usage events” and citations
Project seems to be dead?

31. Considerations
Don’t measure an individual journal’s impact by the
metrics for the entire journal
Cluster of years of citations
Negative citations
A few high impact citations or a lot of low impact
ciations
Source of citing documents
Foreign, conference proceedings, traditional