Impact factor - Wikipedia

Impact factor - Wikipedia
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Measure of relative importance of a journal
This article is about a measure of journal influence. For other scopes of research output metrics, see
Citation impact
Part of
a series
on
Citation metrics
Author-level
Composite index
Erdős number
g-index
h-index
Kardashian index
Science-wide author databases
Citation
Analysis
Academic journal publishing reform
DORA
Leiden Manifesto
I4OC
Altmetrics
Article-level
Bibliographic coupling
Bibliometrics
Cartels
Co-citation
Proximity Analysis
Coercive
Dynamics
Index
Graph
Scientometrics
Journal-level
CiteScore
Eigenfactor
Impact factor
SCImago
The
impact factor
IF
) or
journal impact factor
JIF
) of an
academic journal
is a type of
journal ranking
. Journals with higher impact factor values are considered more prestigious or important within their field. Impact factor is a
scientometric
index calculated by
Clarivate
's
Web of Science
. The impact factor of a journal reflects the yearly mean number of article
citations
published in the last two years. While frequently used by universities and funding bodies to decide on promotion and research proposals, it has been criticised for distorting good scientific practices.
History
edit
The impact factor was devised by
Eugene Garfield
, the founder of the
Institute for Scientific Information
(ISI) in Philadelphia. Impact factors began to be calculated yearly starting from 1975 for journals listed in the
Journal Citation Reports
(JCR). ISI was acquired by
Thomson Scientific & Healthcare
in 1992,
and became known as Thomson ISI. In 2018,
Thomson-Reuters
spun off and sold ISI to
Onex Corporation
and
Baring Private Equity Asia
They founded a new corporation, Clarivate, which continued publishing the JCR.
Calculation
edit
In any given year, the two-year impact factor
{\displaystyle IF_{year}^{J}}
of
Journal J
is the number of citations that all articles published
by
Journal J
in the two previous years received
from
publications by whatever journal in that given year; normalized by the total number of articles published by
Journal J
in the two previous years:
{\displaystyle IF_{year}^{J}={\frac {Cite_{year}(year-2)+Cite_{year}(year-1)}{Pub^{J}(year-2)+Pub^{J}(year-1)}}.}
For example,
Nature
published a total of 1,782 articles in the
2015/2016
biennium (902 articles in 2015 and 880 in 2016); and 74,090 references listed by articles published (by any journal) in 2017 were sourced from within the group of 1,782 articles that
Nature
had published during the previous two years.
These figures yielded an impact factor of
2017
2017
2015
2017
2016
2015
2016
{\displaystyle IF_{2017}^{Nature}={\frac {Cite_{2017}(2015)+Cite_{2017}(2016)}{Pub^{Nature}(2015)+Pub^{Nature}(2016)}}}
74090
902
880
41.577.
{\displaystyle ={\frac {74090}{902+880}}=41.577.}
This means that, on average, its papers published in 2015 and 2016 received roughly 42 citations each in 2017. Impact factors are reported in the subsequent year, when all of the previous year's publications have been processed by the indexing agency.
The value of impact factor depends on how to define "citations" and "publications"; the latter are often referred to as "citable items". In current practice, both "citations" and "publications" are defined exclusively by ISI as follows: "Publications" are items that are classed as "article", "review" or "proceedings paper"
10
in the Web of Science (WoS) database; other items like editorials, corrections, notes, retractions and discussions are excluded. WoS is accessible to all registered users, who can independently verify the number of citable items for a given journal. In contrast, the number of citations is extracted not from the WoS database, but from a dedicated JCR database, which is not accessible to general readers. Hence, the commonly used "JCR Impact Factor" is a proprietary value, which is defined and calculated by ISI and can not be verified by external users.
11
New journals, which are indexed from their first published issue, will receive an impact factor after two years of indexing; in this case, the citations to the year prior to volume 1, and the number of articles published in the year prior to volume 1, are known zero values. Journals that are indexed starting with a volume other than the first volume will not get an impact factor until they have been indexed for three years. Occasionally,
Journal Citation Reports
assigns an impact factor to new journals with less than two years of indexing, based on partial citation data.
12
13
The calculation always uses two complete and known years of item counts, but for new titles one of the known counts is zero. Annuals and other irregular publications sometimes publish no items in a particular year, affecting the count. The impact factor relates to a specific time period; it is possible to calculate it for any desired period. For example, the JCR also includes a
five-year impact factor
, which is calculated by dividing the number of citations to the journal in a given year by the number of articles published in that journal in the previous five years.
14
15
Use
edit
While originally invented as a tool to help university librarians to decide which journals to purchase, the impact factor soon became used as a measure for judging academic success. This use of impact factors was summarised by Hoeffel in 1998:
16
Impact Factor is not a perfect tool to measure the quality of articles but there is nothing better and it has the advantage of already being in existence and is, therefore, a good technique for scientific evaluation. Experience has shown that in each specialty the best journals are those in which it is most difficult to have an article accepted, and these are the journals that have a high impact factor. Most of these journals existed long before the impact factor was devised. The use of impact factor as a measure of quality is widespread because it fits well with the opinion we have in each field of the best journals in our specialty....In conclusion, prestigious journals publish papers of high level. Therefore, their impact factor is high, and not the contrary.
As impact factors are a journal-level metric, rather than an article- or individual-level metric, this use is controversial. Eugene Garfield, the inventor of the JIF agreed with Hoeffel,
17
but warned about the "misuse in evaluating individuals" because there is "a wide variation [of citations] from article to article within a single journal".
18
Despite this warning, the use of the JIF has evolved, playing a key role in the process of assessing individual researchers, their job applications and their funding proposals. In 2007,
The Journal of Cell Biology
noted that:
Impact factor data ... have a strong influence on the scientific community, affecting decisions on where to publish, whom to promote or hire, the success of grant applications, and even salary bonuses.
19
More targeted research has begun to provide firm evidence of how deeply the impact factor is embedded within formal and informal research assessment processes. A review in 2019 studied how often the JIF featured in documents related to the review, promotion, and tenure of scientists in US and Canadian universities. It concluded that 40% of universities focused on academic research specifically mentioned the JIF as part of such review, promotion, and tenure processes.
20
A 2017 study of how researchers in the life sciences behave concluded that "everyday decision-making practices as highly governed by pressures to publish in high-impact journals." It has been argued that the deeply embedded nature of such indicators not only affects research assessment, but the more fundamental issue of what research is actually undertaken: "Given the current ways of evaluation and valuing research, risky, lengthy, and unorthodox project rarely take center stage."
21
Criticism
edit
Numerous critiques have been made regarding the use of impact factors, both in terms of their statistical validity and also of their implications for how science is carried out and assessed.
22
23
24
A 2007 study noted that the most fundamental flaw is that impact factors present the
mean
of data that are not
normally distributed
, and suggested that it would be more appropriate to present the
median
of these data.
19
There is also a more general debate on the validity of the impact factor as a measure of journal importance and the effect of policies that editors may adopt to boost their impact factor (perhaps to the detriment of readers and writers). Other criticism focuses on the effect of the impact factor on the behavior of scholars, editors and other stakeholders.
25
Criticism of impact factors also extends to its impact on researcher behavior. While the emphasis on high-impact journals may lead to strategic publishing practices that prioritize journal prestige over the quality and relevance of research, it's important to acknowledge the "privilege paradox".
26
Younger researchers, particularly those from under-represented regions, often lack the established reputation or networks to secure recognition outside of these metrics.
26
This can lead to a narrow focus on publishing in top-tier journals, potentially compromising the diversity of research topics and methodologies. Further criticisms argue that emphasis on impact factor results from the negative influence of
neoliberal
politics on academia. Some of these arguments demand not just replacement of the impact factor with more sophisticated metrics but also discussion on the social value of research assessment and the growing precariousness of scientific careers in higher education.
27
28
Inapplicability of impact factor to individuals and between-discipline differences
edit
It has been stated that impact factors in particular and citation analysis in general are affected by field-dependent factors
29
which invalidate comparisons not only across disciplines but even within different fields of research of one discipline.
30
The percentage of total citations occurring in the first two years after publication also varies highly among disciplines from 1–3% in the mathematical and physical sciences to 5–8% in the biological sciences.
31
Thus impact factors cannot be used to compare journals across disciplines.
Impact factors are sometimes used to evaluate not only the journals but the papers therein, thereby devaluing papers in certain subjects.
32
In 2004, the
Higher Education Funding Council for England
was urged by the
House of Commons
Science and Technology Select Committee
to remind
Research Assessment Exercise
panels that they are obliged to assess the quality of the content of individual articles, not the reputation of the journal in which they are published.
33
Other studies have repeatedly stated that impact factor is a metric for journals and should not be used to assess individual researchers or institutions.
34
35
36
Questionable editorial policies that affect the impact factor
edit
See also:
Conflicts of interest in academic publishing § COIs of journals
Because impact factor is commonly accepted as a proxy for research quality, some journals adopt editorial policies and practices, some acceptable and some of dubious purpose, to increase their impact factor.
37
38
For example, journals may publish a larger percentage of
review articles
which generally are cited more than research reports.
Research undertaken in 2020 on dentistry journals concluded that the publication of "systematic reviews have significant effect on the Journal Impact Factor ... while papers publishing clinical trials bear no influence on this factor. Greater yearly average of published papers ... means a higher impact factor."
39
Journals may also attempt to limit the number of "citable items"—i.e., the denominator of the impact factor equation—either by declining to publish articles that are unlikely to be cited (such as case reports in medical journals) or by altering articles (e.g., by not allowing an
abstract
or
bibliography
in hopes that Journal Citation Reports will not deem it a "citable item"). As a result of negotiations over whether items are "citable", impact factor variations of more than 300% have been observed.
40
Items considered to be uncitable—and thus are not incorporated in impact factor calculations—can, if cited, still enter into the numerator part of the equation despite the ease with which such citations could be excluded. This effect is hard to evaluate, for the distinction between editorial comment and short original articles is not always obvious. For example, letters to the editor may be part of either class.
Another less insidious tactic journals employ is to publish a large portion of its papers, or at least the papers expected to be highly cited, early in the calendar year. This gives those papers more time to gather citations. Several methods, not necessarily with nefarious intent, exist for a journal to cite articles in the same journal which will increase the journal's impact factor.
41
42
Beyond editorial policies that may skew the impact factor, journals can take overt steps to
game the system
. For example, in 2007, the specialist journal
Folia Phoniatrica et Logopaedica
, with an impact factor of 0.66, published an editorial that cited all its articles from 2005 to 2006 in a protest against the "absurd scientific situation in some countries" related to use of the impact factor.
43
The large number of citations meant that the impact factor for that journal increased to 1.44. As a result of the increase, the journal was not included in the 2008 and 2009
Journal Citation Reports
44
Coercive citation
is a practice in which an editor forces an author to add extraneous citations to an article before the journal will agree to publish it, in order to inflate the journal's impact factor.
45
A survey published in 2012 indicates that coercive citation has been experienced by one in five researchers working in economics, sociology, psychology, and multiple business disciplines, and it is more common in business and in journals with a lower impact factor.
46
Editors of leading business journals banded together to disavow the practice.
47
However, cases of coercive citation have occasionally been reported for other disciplines.
48
Assumed correlation between impact factor and quality
edit
The journal impact factor was originally designed by Eugene Garfield as a metric to help librarians make decisions about which journals were worth indexing, as the JIF aggregates the number of citations to articles published in each journal. Since then, the JIF has become associated as a mark of journal "quality", and gained widespread use for evaluation of research and researchers instead, even at the institutional level. It thus has significant impact on steering research practices and behaviours.
49
50
By 2010, national and international research funding institutions were already starting to point out that numerical indicators such as the JIF should not be considered as a measure of quality.
note 1
In fact, research was indicating that the JIF is a highly manipulated metric,
51
52
53
and the justification for its continued widespread use beyond its original narrow purpose seems due to its simplicity (easily calculable and comparable number), rather than any actual relationship to research quality.
54
55
56
Empirical evidence shows that the misuse of the JIF—and journal ranking metrics in general—has a number of negative consequences for the scholarly communication system. These include gaps between the reach of a journal and the quality of its individual papers
24
and insufficient coverage of social sciences and humanities as well as research outputs from across Latin America, Africa, and South-East Asia.
57
Additional drawbacks include the marginalization of research in
vernacular languages
and on locally relevant topics and inducement to unethical authorship and citation practices. More generally, the impact factor fosters a reputation economy, where scientific success is based on publishing in prestigious journals ahead of actual research qualities such as rigorous methods, replicability and social impact. Using journal prestige and the JIF to cultivate a competition regime in academia has been shown to have deleterious effects on research quality.
58
A number of regional and international initiatives are now providing and suggesting alternative research assessment systems, including key documents such as the
Leiden Manifesto
note 2
and the
San Francisco Declaration on Research Assessment
(DORA).
Plan S
calls for a broader adoption and implementation of such initiatives alongside fundamental changes in the scholarly communication system.
note 3
As appropriate measures of quality for authors and research, concepts of research excellence should be remodelled around transparent workflows and accessible research results.
59
60
61
JIFs are still regularly used to evaluate research in many countries, which is a problem since a number of issues remain around the opacity of the metric and the fact that it is often negotiated by publishers.
62
63
19
Negotiated values
edit
Results of an impact factor can change dramatically depending on which items are considered as "citable" and therefore included in the denominator.
64
One notorious example of this occurred in 1988 when it was decided that meeting abstracts published in
FASEB Journal
would no longer be included in the denominator. The journal's impact factor jumped from 0.24 in 1988 to 18.3 in 1989.
65
Publishers routinely discuss with Clarivate how to improve the "accuracy" of their journals' impact factor and therefore get higher scores.
40
24
Such discussions routinely produce "negotiated values" which result in dramatic changes in the observed scores for dozens of journals, sometimes after unrelated events like the purchase by one of the larger publishers.
66
Distribution skewness
edit
Journal impact factors are influenced heavily by a small number of highly cited papers. Most papers published in 2013–14 received many fewer citations than indicated by the impact factor. Two journals (
Nature
[blue] and
PLOS ONE
[orange]) are shown to represent a highly cited and less cited journal, respectively. The high citation impact of
Nature
is derived from relatively few highly cited papers. Modified after Callaway 2016.
67
Because citation counts have highly
skewed distributions
23
the mean number of citations is potentially misleading if used to gauge the typical impact of articles in the journal rather than the overall impact of the journal itself.
68
For example, about 90% of
Nature
s 2004 impact factor was based on only a quarter of its publications. Thus the actual number of citations for a single article in the journal is in most cases much lower than the mean number of citations across articles.
69
Furthermore, the strength of the relationship between impact factors of journals and the citation rates of the papers therein has been steadily decreasing since articles began to be available digitally.
70
The effect of outliers can be seen in the case of the article "A short history of SHELX", which included this sentence: "This paper could serve as a general literature citation when one or more of the open-source SHELX programs (and the Bruker AXS version SHELXTL) are employed in the course of a crystal-structure determination". This article received more than 6,600 citations. As a consequence, the impact factor of the journal
Acta Crystallographica
Section A
rose from 2.051 in 2008 to 49.926 in 2009, more than
Nature
(at 31.434) and
Science
(at 28.103).
71
The second-most cited article in
Acta Crystallographica Section A
in 2008 had only 28 citations.
72
Critics of the JIF state that use of the
arithmetic mean
in its calculation is problematic because the pattern of citation distribution is skewed
73
and citation distributions metrics have been proposed as an alternative to impact factors.
74
75
76
However, there have also been pleas to take a more nuanced approach to judging the distribution skewness of the impact factor. Ludo Waltman and Vincent Antonio Traag, in their 2021 paper, ran numerous simulations and concluded that "statistical objections against the use of the IF at the level of individual articles are not convincing", and that "the IF may be a more accurate indicator of the value of an article than the number of citations of the article".
Reproducibility
edit
While the underlying mathematical model is publicly known, the dataset which is used to calculate the JIF is not publicly available. This prompted criticism: "Just as scientists would not accept the findings in a scientific paper without seeing the primary data, so should they not rely on Thomson Scientific's impact factor, which is based on hidden data".
19
However, a 2019 article demonstrated that "with access to the data and careful cleaning, the JIF can be reproduced", although this required much labour to achieve.
77
A 2020 research paper went further. It indicated that by querying open access or partly open-access databases, like Google Scholar, ResearchGate, and Scopus, it is possible to calculate approximate impact factors without the need to purchase Web of Science / JCR.
78
Broader negative impact on science
edit
Just as the impact factor has attracted criticism for various immediate problems associated with its application, so has there also been criticism that its application undermines the broader process of science. Research has indicated that bibliometrics figures, particularly the impact factor, decrease the quality of peer review an article receives,
79
cause a reluctance to share data,
21
decrease the quality of articles,
80
and a reduce the scope of publishable research. "For many researchers the only research questions and projects that appear viable are those that can meet the demand of scoring well in terms of metric performance indicators – and chiefly the journal impact factor."
21
Furthermore, the process of publication and science is slowed down – authors automatically try and publish with the journals with the highest impact factor – "as editors and reviewers are tasked with reviewing papers that are not submitted to the most appropriate venues".
77
Institutional responses to criticism of the impact factor
edit
Given the growing criticism and its widespread usage as a means of research assessment, organisations and institutions have begun to take steps to move away from the journal impact factor. In November 2007 the
European Association of Science Editors
(EASE) issued an official statement recommending "that journal impact factors are used only—and cautiously—for measuring and comparing the influence of entire journals, but not for the assessment of single papers, and certainly not for the assessment of researchers or research programmes".
81
In July 2008, the
International Council for Science
Committee on Freedom and Responsibility in the Conduct of Science issued a "statement on publication practices and indices and the role of
peer review
in research assessment", suggesting many possible solutions—e.g., considering a limit number of publications per year to be taken into consideration for each scientist, or even penalising scientists for an excessive number of publications per year—e.g., more than 20.
82
In February 2010, the
German Research Foundation
published new guidelines to reduce the number of publications that could be submitted when applying for funding: "The focus has not been on what research someone has done but rather how many papers have been published and where." They noted that for decisions concerning "performance-based funding allocations, postdoctoral qualifications, appointments, or reviewing funding proposals, [where] increasing importance has been given to numerical indicators such as the
h-index
and the impact factor".
83
The UK's
Research Assessment Exercise
for 2014 also banned the journal impact factor
84
although evidence suggested that this ban was often ignored.
85
In response to growing concerns over the inappropriate use of journal impact factors in evaluating scientific outputs and scientists themselves, the
American Society for Cell Biology
together with a group of editors and publishers of scholarly journals created the
San Francisco Declaration on Research Assessment
(DORA). Released in May 2013, DORA has garnered support from thousands of individuals and hundreds of institutions,
28
including in March 2015 the League of European Research Universities (a consortium of 21 of the most renowned research universities in Europe),
86
who have endorsed the document on the DORA website.
Publishers, even those with high impact factors, also recognised the flaws.
87
Nature
magazine criticised the over-reliance on JIF, pointing not just to its statistical flaws but to negative effects on science: "The resulting pressures and disappointments are nothing but demoralizing, and in badly run labs can encourage sloppy research that, for example, fails to test assumptions thoroughly or to take all the data into account before submitting big claims."
22
Various publishers now use a mixture of metrics on their website; the PLOS series of journals does not display the impact factor.
88
Microsoft Academic took a similar view, stating that h-index, EI/SCI and journal impact factors are not shown because "the research literature has provided abundant evidence that these metrics are at best a rough approximation of research impact and scholarly influence."
89
In 2021,
Utrecht University
promised to abandon all quantitative bibliometrics, including the impact factor. The university stated that "it has become a very sick model that goes beyond what is really relevant for science and putting science forward".
90
91
This followed a 2018 decision by the main Dutch funding body for research,
NWO
, to remove all references to journal impact factors and the h-index in all call texts and application forms.
92
Utrecht's decision met with some resistance. An open letter signed by over 150 Dutch academics argued that, while imperfect, the JIF is still useful, and that omitting it "will lead to randomness and a compromising of scientific quality".
93
Related indices
edit
Some related metrics, also calculated and published by the same organization, include:
Cited half-life
: the median age of the articles that were cited in
Journal Citation Reports
each year. For example, if a journal's half-life in 2005 is 5, that means the citations from 2001 to 2005 are half of all the citations from that journal in 2005, and the other half of the citations precede 2001.
94
Aggregate impact factor
for a subject category: it is calculated taking into account the number of citations to all journals in the subject category and the number of articles from all the journals in the subject category.
Immediacy index
: the number of citations the articles in a journal receive in a given year divided by the number of articles published.
Journal citation indicator
JCI
): a JIF that adjusts for scientific field; it is similar to
Source Normalized Impact per Paper
, calculated based on the
Scopus
database.
95
JCI is available for all journals in the
Web of Science Core Collection
(WoS CC) -- including the AHCI, ESCI, BCI, CPCI—while JIF is only available for the SCIE and SSCI; however, starting in June 2023, JIF will also be issued for all journals in the WoS CC.
96
JIF quartile ranking
: a rank based on the four
quartiles
within a given subject or topic category.
97
JIF percentile ranking
: a
percentile rank
computed for a particular subject category.
98
A given journal may attain a different quartile or percentile in different categories.
As with the impact factor, there are some nuances to this: for example, Clarivate excludes certain article types (such as news items, correspondence, and errata) from the denominator.
99
100
101
10
Other measures of scientific impact
edit
Main article:
Citation metrics
Further information:
Scientometrics
Additional
journal-level metrics
are available from other organizations. For example,
CiteScore
is a metric for serial titles in
Scopus
launched in December 2016 by
Elsevier
102
103
While these metrics apply only to journals, there are also
author-level metrics
, such as the
h-index
, that apply to individual researchers. In addition,
article-level metrics
measure impact at an article level instead of journal level.
Other more general alternative metrics, or "
altmetrics
", that include article views, downloads, or mentions in
social media
, offer a different perspective on research impact, concentrating more on immediate social impact in and outside academia.
61
104
Counterfeit impact factors
edit
Fake impact factors or bogus impact factors are produced by certain companies or individuals.
105
According to an article published in the
Electronic Physician
, these include Global Impact Factor, Citefactor, and Universal Impact Factor.
105
Jeffrey Beall
maintained a list of such misleading metrics.
106
107
Another deceitful practice is reporting "alternative impact factors", calculated as the average number of citations per article using
citation indices
other than JCR such as
Google Scholar
(e.g., "Google-based Journal Impact Factor") or
Microsoft Academic
108
False impact factors are often used by
predatory publishers
109
110
Consulting Journal Citation Reports' master journal list can confirm if a publication is
indexed
by the
Journal Citation Reports
111
The use of fake impact metrics is considered a
red flag
112
See also
edit
Science portal
Author impact factor
Citation impact
Goodhart's law
Journalology
Notes on alternatives
edit
'Quality Not Quantity' – DFG Adopts Rules to Counter the Flood of Publications in Research"
(Press release). Deutsche Forschungsgemeinschaft (
German Research Foundation
). 2010. DFG Press Release No. 7.
"The Leiden Manifesto for Research Metrics"
. 2015.
"Plan S implementation guidelines"
. February 2019.
References
edit
Waltman, Ludo; Traag, Vincent Antonio (1 March 2021).
"Use of the journal impact factor for assessing individual articles: Statistically flawed or not?"
F1000Research
: 366.
doi
10.12688/f1000research.23418.2
PMC
7974631
PMID
33796272
Curry S (February 2018). "Let's move beyond the rhetoric: it's time to change how we judge research".
Nature
554
(7691): 147.
Bibcode
2018Natur.554..147C
doi
10.1038/d41586-018-01642-w
PMID
29420505
Hutchins, BI; Yuan, X; Anderson, JM; Santangelo, GM (September 2016).
"Relative Citation Ratio (RCR): A New Metric That Uses Citation Rates to Measure Influence at the Article Level"
PLOS Biology
14
(9) e1002541.
doi
10.1371/journal.pbio.1002541
PMC
5012559
PMID
27599104
"Thomson Corporation acquired ISI"
Online
. July 1992. Archived from
the original
on 15 May 2013
. Retrieved
26 February
2012
"Acquisition of the Thomson Reuters Intellectual Property and Science Business by Onex and Baring Asia Completed"
(Press release). 3 October 2016.
"Journal Citation Reports"
Web of Science Group
. Retrieved
14 September
2019
"Web of Science Group"
Web of Science Group
. 5 August 2019
. Retrieved
28 July
2020
"The Clarivate Impact Factor"
Clarivate
. 20 June 1994.
"Nature".
2017 Journal Citation Reports
Web of Science
(Science ed.).
Thomson Reuters
. 2018.
McVeigh ME, Mann SJ (September 2009).
"The journal impact factor denominator: defining citable (counted) items"
JAMA
302
(10):
1107–
9.
doi
10.1001/jama.2009.1301
PMID
19738096
Hubbard SC, McVeigh ME (2011).
"Casting a wide net: The Journal Impact Factor numerator"
Learned Publishing
24
(2):
133–
137.
doi
10.1087/20110208
S2CID
20172401
"RSC Advances receives its first partial impact factor"
RSC Advances Blog
. 24 June 2013
. Retrieved
16 July
2018
Konforti, Boyana (30 July 2014).
"Our first (partial) impact factor and our continuing (full) story"
Cell Mentor
"JCR with Eigenfactor"
. Archived from
the original
on 2 January 2010
. Retrieved
26 August
2009
"ISI 5-Year Impact Factor"
APA
. Retrieved
12 November
2017
Hoeffel C (December 1998). "Journal impact factors".
Allergy
53
(12): 1225.
doi
10.1111/j.1398-9995.1998.tb03848.x
PMID
9930604
S2CID
5773127
Garfield E (January 2006). "The history and meaning of the journal impact factor".
JAMA
295
(1):
90–
3.
Bibcode
2006JAMA..295...90G
doi
10.1001/jama.295.1.90
PMID
16391221
S2CID
31183037
Garfield E (June 1998).
"[The impact factor and its proper application]"
Der Unfallchirurg
101
(6):
413–
4.
PMID
9677838
Rossner M, Van Epps H, Hill E (December 2007).
"Show me the data"
The Journal of Cell Biology
179
(6):
1091–
2.
doi
10.1083/jcb.200711140
PMC
2140038
PMID
18086910
McKiernan EC, Schimanski LA, Muñoz Nieves C, Matthias L,
Niles MT
, Alperin JP (July 2019).
"Use of the Journal Impact Factor in academic review, promotion, and tenure evaluations"
eLife
e47338.
doi
10.7554/eLife.47338
PMC
6668985
PMID
31364991
Müller, Ruth; de Rijcke, Sarah (1 July 2017).
"Thinking with indicators. Exploring the epistemic impacts of academic performance indicators in the life sciences"
Research Evaluation
26
(3):
157–
168.
doi
10.1093/reseval/rvx023
ISSN
0958-2029
"Time to remodel the journal impact factor"
Nature
535
(7613): 466. July 2016.
Bibcode
2016Natur.535..466.
doi
10.1038/535466a
PMID
27466089
Callaway E (July 2016).
"Beat it, impact factor! Publishing elite turns against controversial metric"
Nature
535
(7611):
210–
1.
Bibcode
2016Natur.535..210C
doi
10.1038/nature.2016.20224
PMID
27411614
Brembs, Björn; Button, Katherine; Munafò, Marcus (24 June 2013).
"Deep impact: unintended consequences of journal rank"
Frontiers in Human Neuroscience
: 291.
arXiv
1301.3748
Bibcode
2013arXiv1301.3748B
doi
10.3389/fnhum.2013.00291
ISSN
1662-5161
PMC
3690355
PMID
23805088
van Wesel M (February 2016).
"Evaluation by Citation: Trends in Publication Behavior, Evaluation Criteria, and the Strive for High Impact Publications"
Science and Engineering Ethics
22
(1):
199–
225.
doi
10.1007/s11948-015-9638-0
PMC
4750571
PMID
25742806
Souza-Neto, Valério (12 November 2024).
"Ignoring journal metrics on CVs is an act of privilege"
Nature
635
(8038): 290.
Bibcode
2024Natur.635..290S
doi
10.1038/d41586-024-03705-7
PMID
39533078
Kansa E (27 January 2014).
"It's the Neoliberalism, Stupid: Why instrumentalist arguments for Open Access, Open Data, and Open Science are not enough"
LSE Impact Blog
. Retrieved
16 July
2018
Cabello F, Rascón MT (2015).
"The Index and the Moon. Mortgaging Scientific Evaluation"
International Journal of Communication
1880–
1887.
Bornmann L, Daniel HD (2008). "What do citation counts measure? A review of studies on citing behavior".
Journal of Documentation
64
(1):
45–
80.
doi
10.1108/00220410810844150
hdl
11858/00-001M-0000-0013-7A94-3
S2CID
17260826
Anauati MV, Galiani S, Gálvez RM (11 November 2014). "Quantifying the Life Cycle of Scholarly Articles Across Fields of Economic Research".
SSRN
2523078
van Nierop E (2009). "Why Do Statistics Journals Have Low Impact Factors?".
Statistica Neerlandica
63
(1):
52–
62.
doi
10.1111/j.1467-9574.2008.00408.x
S2CID
247704905
Bohannon J (2016). "Hate journal impact factors? New study gives you one more reason".
Science
doi
10.1126/science.aag0643
"House of Commons – Science and Technology – Tenth Report"
. 7 July 2004
. Retrieved
28 July
2008
Seglen PO (February 1997).
"Why the impact factor of journals should not be used for evaluating research"
BMJ
314
(7079):
498–
502.
doi
10.1136/bmj.314.7079.497
PMC
2126010
PMID
9056804
"EASE Statement on Inappropriate Use of Impact Factors"
European Association of Science Editors
. November 2007. Archived from
the original
on 14 August 2012
. Retrieved
13 April
2013
Wilsdon J, Allen L, Belfiore E, Campbell P, Curry S, Hill S, et al. (July 2015). The Metric Tide: Report of the Independent Review of the Role of Metrics in Research Assessment and Management (Report).
doi
10.13140/RG.2.1.4929.1363
Monastersky R (14 October 2005).
"The Number That's Devouring Science"
The Chronicle of Higher Education
Arnold DN
, Fowler KK (2011). "Nefarious Numbers".
Notices of the American Mathematical Society
58
(3):
434–
437.
arXiv
1010.0278
Bibcode
2010arXiv1010.0278A
Valderrama P, Escabias M, Valderrama MJ, Jiménez-Contreras E, Baca P (March 2020).
"Influential variables in the Journal Impact Factor of Dentistry journals"
Heliyon
(3) e03575.
Bibcode
2020Heliy...603575V
doi
10.1016/j.heliyon.2020.e03575
PMC
7082530
PMID
32211547
The PLoS Medicine Editors (June 2006).
"The impact factor game. It is time to find a better way to assess the scientific literature"
PLOS Medicine
(6) e291.
doi
10.1371/journal.pmed.0030291
PMC
1475651
PMID
16749869
Agrawal AA (April 2005).
"Corruption of journal Impact Factors"
(PDF)
Trends in Ecology & Evolution
20
(4): 157.
Bibcode
2005TEcoE..20..157A
doi
10.1016/j.tree.2005.02.002
PMID
16701362
. Archived from
the original
(PDF)
on 19 June 2010.
Fassoulaki A, Papilas K, Paraskeva A, Patris K (August 2002). "Impact factor bias and proposed adjustments for its determination".
Acta Anaesthesiologica Scandinavica
46
(7):
902–
5.
doi
10.1034/j.1399-6576.2002.460723.x
PMID
12139549
S2CID
20805963
Schutte HK, Svec JG (2007). "Reaction of Folia Phoniatrica et Logopaedica on the current trend of impact factor measures".
Folia Phoniatrica et Logopaedica
59
(6):
281–
5.
doi
10.1159/000108334
PMID
17965570
S2CID
7595296
"Journal Citation Reports – Notices"
. Archived from
the original
on 15 May 2010
. Retrieved
24 September
2009
McLeod S (25 September 2020).
"Should authors cite sources suggested by peer reviewers? Six antidotes for handling potentially coercive reviewer citation suggestions"
Learned Publishing
34
(2):
282–
286.
doi
10.1002/leap.1335
ISSN
0953-1513
S2CID
225004022
Wilhite AW, Fong EA (February 2012). "Scientific publications. Coercive citation in academic publishing".
Science
335
(6068):
542–
3.
Bibcode
2012Sci...335..542W
doi
10.1126/science.1212540
PMID
22301307
S2CID
30073305
Lynch JG (March 2012). "Business journals combat coercive citation".
Science
335
(6073): 1169.1–1169.
Bibcode
2012Sci...335.1169L
doi
10.1126/science.335.6073.1169-a
PMID
22403371
Dyer C (February 1997).
"Widow can be inseminated with husband's sperm"
BMJ
314
(7079): 461.
doi
10.1136/bmj.314.7079.461d
PMC
2125988
PMID
9056791
Gargouri Y, Hajjem C, Lariviere V, Gingras Y, Carr L, Brody T, Harnad S (2018). "The Journal Impact Factor: A Brief History, Critique, and Discussion of Adverse Effects".
arXiv
1801.08992
cs.DL
].
Al-Hoorie A, Vitta JP (2019). "The seven sins of L2 research: A review of 30 journals' statistical quality and their CiteScore, SJR, SNIP, JCR Impact Factors".
Language Teaching Research
23
(6):
727–
744.
doi
10.1177/1362168818767191
S2CID
149857357
Falagas ME, Alexiou VG (2008). "The top-ten in journal impact factor manipulation".
Archivum Immunologiae et Therapiae Experimentalis
56
(4):
223–
6.
doi
10.1007/s00005-008-0024-5
PMID
18661263
S2CID
7482376
Tort AB, Targino ZH, Amaral OB (2012).
"Rising publication delays inflate journal impact factors"
PLOS ONE
(12) e53374.
Bibcode
2012PLoSO...753374T
doi
10.1371/journal.pone.0053374
PMC
3534064
PMID
23300920
Fong EA, Wilhite AW (2017).
"Authorship and citation manipulation in academic research"
PLOS ONE
12
(12) e0187394.
Bibcode
2017PLoSO..1287394F
doi
10.1371/journal.pone.0187394
PMC
5718422
PMID
29211744
Adler R, Ewing J, Taylor P (2009).
"Citation Statistics: A Report from the International Mathematical Union (IMU) in Cooperation with the International Council of Industrial and Applied Mathematics (ICIAM) and the Institute of Mathematical Statistics (IMS)"
(PDF)
Statistical Science
24
(1):
1–
14.
arXiv
0910.3529
doi
10.1214/09-STS285
ISSN
0883-4237
JSTOR
20697661
S2CID
219477
Brembs B (2018).
"Prestigious Science Journals Struggle to Reach Even Average Reliability"
Frontiers in Human Neuroscience
12
37.
doi
10.3389/fnhum.2018.00037
PMC
5826185
PMID
29515380
Gargouri Y, Hajjem C, Lariviere V, Gingras Y, Carr L, Brody T, Harnad S (2009). "The Impact Factor's Matthew Effect: A Natural Experiment in Bibliometrics".
arXiv
0908.3177
physics.soc-ph
].
Severin, Anna; Strinzel, Michaela; Egger, Matthias; Barros, Tiago; Sokolov, Alexander; Mouatt, Julia Vilstrup; Müller, Stefan (29 August 2023). Dirnagl, Ulrich (ed.).
"Relationship between journal impact factor and the thoroughness and helpfulness of peer reviews"
PLOS Biology
21
(8) e3002238.
doi
10.1371/journal.pbio.3002238
eISSN
1545-7885
ISSN
1544-9173
LCCN
2003212293
OCLC
1039259630
PMC
10464996
PMID
37643173
Vessuri, Hebe; Guédon, Jean-Claude; Cetto, Ana María (September 2014).
"Excellence or quality? Impact of the current competition regime on science and scientific publishing in Latin America and its implications for development"
Current Sociology
62
(5):
647–
665.
doi
10.1177/0011392113512839
eISSN
1461-7064
ISSN
0011-3921
S2CID
25166127
– via
Sage Publishing
Moore S, Neylon C, Eve MP, O'Donnell DP, Pattinson D (2017).
'Excellence R Us': University Research and the Fetishisation of Excellence"
Palgrave Communications
16105.
doi
10.1057/palcomms.2016.105
Owen R, Macnaghten P, Stilgoe J (2012). "Responsible Research and Innovation: From Science in Society to Science for Society, with Society".
Science and Public Policy
39
(6):
751–
760.
doi
10.1093/scipol/scs093
Hicks D, Wouters P, Waltman L, de Rijcke S, Rafols I (April 2015).
"Bibliometrics: The Leiden Manifesto for research metrics"
Nature
520
(7548):
429–
31.
Bibcode
2015Natur.520..429H
doi
10.1038/520429a
hdl
10261/132304
PMID
25903611
"Open Access and the Divide between 'Mainstream" and "peripheral".
Como Gerir e Qualificar Revistas Científicas
1–
25.
Alperin JP, Muñoz Nieves C, Schimanski LA, Fischman GE,
Niles MT
, McKiernan EC (February 2019).
"How significant are the public dimensions of faculty work in review, promotion and tenure documents?"
eLife
e42254.
doi
10.7554/eLife.42254
PMC
6391063
PMID
30747708
Adam D (February 2002).
"The counting house"
Nature
415
(6873):
726–
9.
doi
10.1038/415726a
PMID
11845174
S2CID
4407346
Baylis M, Gravenor M, Kao R (September 1999).
"Sprucing up one's impact factor"
Nature
401
(6751): 322.
doi
10.1038/43768-c1
PMID
10517624
S2CID
4356889
Brembs B (8 January 2016).
"Just how widespread are impact factor negotiations?"
. Retrieved
14 July
2020
Callaway E (July 2016).
"Beat it, impact factor! Publishing elite turns against controversial metric"
Nature
535
(7611):
210–
1.
Bibcode
2016Natur.535..210C
doi
10.1038/nature.2016.20224
PMID
27411614
Joint Committee on Quantitative Assessment of Research (12 June 2008).
"Citation Statistics"
(PDF)
. International Mathematical Union.
"Not-so-deep impact"
Nature
435
(7045):
1003–
4. June 2005.
doi
10.1038/4351003b
PMID
15973362
Lozano GA, Larivière V, Gingras Y (2012). "The weakening relationship between the impact factor and papers' citations in the digital age".
Journal of the American Society for Information Science and Technology
63
(11):
2140–
2145.
arXiv
1205.4328
Bibcode
2012arXiv1205.4328L
doi
10.1002/asi.22731
S2CID
492922
Grant B (21 June 2010).
"New impact factors yield surprises"
The Scientist
. Retrieved
23 October
2024
McVeigh M (17 June 2010).
"What does it mean to be #2 in Impact?"
. Archived from
the original
on 12 October 2017
. Retrieved
16 July
2018
Larivière V, Kiermer V, MacCallum CJ, McNutt M, Patterson M, Pulverer B, et al. (2016). "A Simple Proposal for the Publication of Journal Citation Distributions".
bioRxiv
10.1101/062109
Kiermer V (2016).
"Measuring Up: Impact Factors Do Not Reflect Article Citation Rates"
PLOS
"Ditching Impact Factors for Deeper Data"
The Scientist
. Retrieved
29 July
2016
Corneliussen S (2016). "Bad summer for the journal impact factor".
Physics Today
(8) 22472.
Bibcode
2016PhT..2016h2472C
doi
10.1063/PT.5.8183
Larivière V, Sugimoto CR (2019), Glänzel W, Moed HF, Schmoch U, Thelwall M (eds.), "The Journal Impact Factor: A Brief History, Critique, and Discussion of Adverse Effects",
Springer Handbook of Science and Technology Indicators
, Springer Handbooks, Cham: Springer International Publishing, pp.
3–
24,
arXiv
1801.08992
doi
10.1007/978-3-030-02511-3_1
ISBN
978-3-030-02510-6
S2CID
3677889
{{
citation
}}
: CS1 maint: work parameter with ISBN (
link
Templ M (19 June 2020).
"Modeling and Prediction of the Impact Factor of Journals Using Open-Access Databases: With an Application to the Austrian Journal of Statistics"
Austrian Journal of Statistics
49
(5):
35–
58.
doi
10.17713/ajs.v49i5.1186
ISSN
1026-597X
S2CID
225704065
Stephan, Paula; Veugelers, Reinhilde; Wang, Jian (April 2017).
"Reviewers are blinkered by bibliometrics"
Nature
544
(7651):
411–
412.
Bibcode
2017Natur.544..411S
doi
10.1038/544411a
ISSN
0028-0836
PMID
28447652
S2CID
5197138
"Informing Research Choices: Indicators and Judgment"
. Retrieved
16 August
2021
"EASE Statement on Inappropriate Use of Impact Factors"
European Association of Science Editors
. Archived from
the original
on 14 August 2012
. Retrieved
23 July
2012
"International Council for Science statement"
. Icsu.org. 2 May 2014. Archived from
the original
on 26 April 2017
. Retrieved
18 May
2014
"Quality not Quantity: DFG Adopts Rules to Counter the Flood of Publications in Research"
. Deutsche Forschungsgemeinschaft. 23 February 2010
. Retrieved
16 July
2018
permanent dead link
"Departmental H-Index is a more transparent, fair and cost-effective method for distributing funding to universities"
Impact of Social Sciences
. 8 February 2013
. Retrieved
14 August
2021
"Business as usual in judging the worth of a researcher?"
The Guardian
. 30 November 2012
. Retrieved
14 August
2021
"Not everything that can be counted counts …"
. League of European Research Universities. 16 March 2015. Archived from
the original
on 1 December 2017.
Callaway, Ewen (July 2016).
"Beat it, impact factor! Publishing elite turns against controversial metric"
Nature
535
(7611):
210–
211.
Bibcode
2016Natur.535..210C
doi
10.1038/nature.2016.20224
ISSN
0028-0836
PMID
27411614
S2CID
4452614
"Journal Information"
PLOS ONE
. Retrieved
14 August
2021
"FAQ"
Microsoft Academic
. Archived from
the original
on 5 January 2017
. Retrieved
15 December
2020
Woolston C (July 2021).
"Impact factor abandoned by Dutch university in hiring and promotion decisions"
Nature
595
(7867): 462.
Bibcode
2021Natur.595..462W
doi
10.1038/d41586-021-01759-5
PMID
34172959
S2CID
235647170
"Recognition and rewards | Universiteit Utrecht"
www.uu.nl
. Retrieved
19 July
2021
"DORA | NWO"
www.nwo.nl
. Retrieved
21 July
2021
"Scientists at odds on Utrecht University reforms to hiring and promotion criteria"
www.natureindex.com
. 9 August 2021
. Retrieved
14 August
2021
"Impact Factor, Immediacy Index, Cited Half-life"
. Swedish University of Agricultural Sciences. Archived from
the original
on 23 May 2008
. Retrieved
30 October
2016
O'Grady, Cathleen (30 June 2021).
"Journal impact factor gets a sibling that adjusts for scientific field"
Science | AAAS
. Retrieved
30 June
2021
"Web of Science Journal Evaluation Process and Selection Criteria"
Clarivate
. 26 July 2022
. Retrieved
18 January
2023
"Scientific & Academic Research"
Support
. Clarivate
. Retrieved
25 March
2023
"Journal Impact Factor Percentile"
jcr.help.clarivate.com
. Archived from
the original
on 24 May 2023
. Retrieved
24 May
2023
"Bibliometrics (journal measures)"
Elsevier
. Archived from
the original
on 18 August 2012
. Retrieved
9 July
2012
A measure of the speed at which content in a particular journal is picked up and referred to.
"Glossary of Thomson Scientific Terminology"
Thomson Reuters
. Archived from
the original
on 20 April 2017
. Retrieved
9 July
2012
"Journal Citation Reports Contents – Immediacy Index"
((online))
Clarivate Analytics
. Retrieved
9 July
2012
The Immediacy Index is the average number of times an article is cited in the year it is published. The journal Immediacy Index indicates how quickly articles in a journal are cited. The aggregate Immediacy Index indicates how quickly articles in a subject category are cited.
"Metrics – Features – Scopus – Solutions"
www.elsevier.com
. Retrieved
9 December
2016
Van Noorden R (December 2016).
"Controversial impact factor gets a heavyweight rival"
Nature
540
(7633):
325–
326.
Bibcode
2016Natur.540..325V
doi
10.1038/nature.2016.21131
PMID
27974784
Priem J, Taraborelli D, Groth P, Neylon C (26 October 2010).
"Altmetrics: A manifesto"
. Archived from
the original
on 21 April 2016
. Retrieved
1 January
2020
Jalalian M (2015).
"The story of fake impact factor companies and how we detected them"
Electronic Physician
(2):
1069–
72.
doi
10.14661/2015.1069-1072
PMC
4477767
PMID
26120416
"Misleading Metrics"
Scholarly Open Access
. Archived from
the original
on 11 January 2017.
"Misleading Metrics – Beall's List"
Xia J, Smith MP (2018).
"Alternative journal impact factors in open access publishing"
Learned Publishing
31
(4):
403–
411.
doi
10.1002/leap.1200
ISSN
0953-1513
Beall J.
"Scholarly Open-Access – Fake impact factors"
. Archived from
the original
on 21 March 2016.
Discussion document: Predatory Publishing (Report). Committee on Publication Ethics. 1 November 2019.
doi
10.24318/cope.2019.3.6
"Master Journal List"
Web of Science Group
. Clarivate.
Ebrahimzadeh MH (April 2016).
"Validated Measures of Publication Quality: Guide for Novice Researchers to Choose an Appropriate Journal for Paper Submission"
The Archives of Bone and Joint Surgery
(2):
94–
6.
PMC
4852052
PMID
27200383
Further reading
edit
"Does the 'Impact Factor' Impact Decisions on Where to Publish?"
APS News
15
(4).
American Physical Society
. April 2006
. Retrieved
1 July
2010
Garfield E (October 1999).
"Journal impact factor: a brief review"
CMAJ
161
(8):
979–
80.
PMC
1230709
PMID
10551195
Gilbert N (November 2010).
"UK science will be judged on impact"
Nature
468
(7322): 357.
Bibcode
2010Natur.468..357G
doi
10.1038/468357a
PMID
21085146
Groesser SN (2012).
"Dynamics of Journal Impact Factors"
(PDF)
Systems Research and Behavioral Science
29
(6):
624–
644.
doi
10.1002/sres.2142
. Archived from
the original
(PDF)
on 9 April 2023
. Retrieved
9 August
2022
Lariviere V, Sugimoto CR (2018). "The Journal Impact Factor: A brief history, critique, and discussion of adverse effects".
arXiv
1801.08992
cs.DL
].
Marcus A, Oransky I (22 May 2015).
"What's Behind Big Science Frauds?"
. Opinion.
The New York Times
"Journal & Country Rank: Rankings by Scopus and Scimago Lab"
Scopus and Scimago Lab
. Scimago
. Retrieved
23 October
2018
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