IMPACT FACTOR vs. JOURNAL CITATION FREQUENCY
Source:
ISI Web of Science
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In the beginning, during the late
1950s, it was just an innocent idea
in Eugene Garfield's head. A Philadelphia researcher who described
himself as a "documentation consultant," Mr. Garfield spent his free
time thinking about scientific literature and how to mine information
from it. He eventually dreamed up something he called an "impact
factor," essentially a grading system for journals, that could
help him
pick out the most important publications from the ranks of lesser
titles. .......from Chronicle of
Higher Education, October 14, 2005
The increased publicity of
ISI
Impact
Factor of scientific journals has led to some
misgivings.
Please refer to the
article
published in Nature,
"Not-so-deep impact: Research
assessment rests too heavily on the inflated status of the impact factor"
Nature
Vol. 435, 1003 (23 June 2005). ".....For example,
we have analysed the citations of individual papers.in Nature and found
that 89% of last year’s figure was generated by just 25% of
our papers. ....."
Read the article from Chronicle of Higher
Education, "The Number
That's Devouring Science" -The impact factor, once a simple
way to rank scientific journals,
has become an unyielding yardstick for hiring, tenure, and
grants. Read Chronicle of
Higher Education, October
14, 2005
Similar
viws have also been expressed in another article relatated to education and debate
Why
the impact factor of journals should not be used for evaluating
research (BMJ
1997;314:497, 15 February)
The
Impact
Factor of the scientific
journals
are determined from the
short term citations (two previous years) and does not consider long
term impact. Increase/decrease in number of published
papers in a given year, time
required to publish articles, and publication of popular review
articles
indirectly influence the
Impact Factor.
In order to assess the real
impact of published work, a
Citation
Frequency for published work has
been determined for selected journals during 3 different periods:
1.
Short term (2002-2004); 2. Medium term (1998-2004) and 3. Long
term (1975-2004).
The fraction of the published papers that show significant citations
(25, 50 or 100+ citations); moderate citations (10+ citations) and No
citations are compared for these three differemt periods.
For further
details on the analysis of Citation Frequency please refer to
Citation Frequency =
Number of Papers
with “N” citations/Total Number of Published Papers x100
Where “N” represents
number of papers with at
least 100, 50, 25, 10 or no citations.
Here is a comparision of 30 most cited papers that
were
published in few selected journals during three different
periods. The impact factor of these journals in the Physical
Chemistry/Chemical Physics area vary from 2 -
9. It
is interesting to note that all these journals have published many
papers with impressive citations. If the scientific work is novel
and
significant, it is sure to make an impact irrespective of the journal
impact factor.
(All data presented here was gathered from ISI Web of
Science on August 27, 2005)