relationship with Google, responsible for searching
the content to be analysed.
4.4 The Impact Index of Private
Publications versus Public
Publications
The outcome of the comparisons between the impact
of open and closed publications, including the
metrics used for these comparisons, is still very
incipient. The studies that will be discussed below
refer to specific analyses such as: the comparison of
the impact of publications, both in the repository of
Thomson and ArXiv; the boycott in which
researchers take part against the impact factor of
Thomson; and the ranking of open publications
measured by Google.
The Internet, as an open database, is allowing
users to generate statistics of citation of researches
published free of charge (Butler, 2008). The Open
access is cooperating with giants like Elsevier,
inserting data from its publications on Scopus base,
a database of abstracts created by Elsevier in 2004.
Elsevier also owns the database The SCImago
Journal & Country Rank that makes the analysis of
data stored in the Scopus, concerning the data
mining from the universities of Granada,
Extremadura, Carlos III and Alcalá de Henares, all
in Spain. This database classifies periodicals and
countries that use citation metrics such as H Index,
and also includes a new metric: the SCImago
Journal Rank (SJR). It is difficult to compare the
results of the analyses of SJR with other impact
factors because their database is different.
And, on the other hand, Google Scholar has
already indexed much more from the literature than
the Web of Knowledge or Scopus (Butler D, 2011).
Thomson holds a monopoly on the number of
citations per year and its subscription products
include the Web of Science, the Journal Citation
Report, and the Essential Science Indicators.
However, researchers are negotiating with Thomson,
requesting greater transparency on how the citation
metrics are calculated and on its datasets as well
(Butler D, 2008). In an editorial published in the
Journal of Cell Biology, the head of Rockefeller
University Press and colleagues said that their
analysis of database provided by Thomson showed
different values for the metrics in comparison to
those published by this company (Rossner M, Van
Epps H, Hill E, 2007). And Thomson opened a web
forum to formally respond to this editorial (Thomson
Reuters, 2014).
In 2004, James Pringle, vice president for
development, academic markets, and government of
Thomson ISI, USA, conducted a study on the impact
factor of the entire content of Web of Science,
concerning closed and open access. At that time, the
base had 8,509 closed access journals and 191 open
access journals (Harnad and Brody, 2004). A
rigorous selection was made in this study and only
the journals that were directly accessible on the
Internet, without any cost, fitted the concept of open
access. Among them there were different types of
journals, such as: the BMJ, with a long history and
prestige that migrated to this new model of open
publication; and the Brazilian Journal of
Microbiology, an important regional journal that
uses open access as a way to expand global
awareness. There are several ways to make the
access open and the objectives of each publisher can
be different (Pringle, 2004). The outcome of this
study points out that the open access does neither
result in more nor fewer citations in these journals,
since the increase in the number of readers of
journals does not change the relevance of a
researcher’s article and its fundamental value in a
journal. Moreover, it does not seem that the increase
in the number of potential readers will necessarily
change a journal impact.
However,two researchers disagree with Pringle
when he says that open access journals and non-
open access journals have the same impact.
According to these authors, the comparison was
made between only 2% of OA journals indexed by
the ISI (191), against 98% of non-OA journals
(8,509)(Harnad S, Brody T,2004). New study was
made using the citation database ISI, on a CD-
ROM, with references of 7,000 journals from 1991
to 2001 and the content of arXiv.org. The CD-ROM
ISI had the metadata and references of 14 million
articles, and the arXiv.org base, in January 2004,
had 260,000 complete texts of e-prints. From this
amount, 95,012 articles were found both in the ISI
and arXiv database. The comparison between Open
Access and Non-Open Access articles, in all
Physics fields, from 1992 to 2001, showed that the
superiority of Open Access Citation Impact Ratios,
increases from 253% in 1992, to 557% in
2001(Brody et al., 2004). The access is not a
sufficient condition for citation, but it is necessary.
The OA dramatically increases the number of
potential users by just allowing them to access a
particular article, which otherwise would not be
possible due to its high cost. Thereby, the OA
increases both the use and the impact (Harnad and
Brody, 2004).