The Trends to Multi-Authorship and International Collaborative in
Ecology Papers
João Carlos Nabout1, Marcos Aurélio de Amorim Gomes2, Karine Borges Machado3, Barbbara da Silva Rocha4,
Meirielle Euripa Pádua de Moura5, Raquel Menestrino Ribeiro6, Lorraine dos Santos Rocha7, José Alexandre
Felizola Diniz-Filho8 and Ramiro Logares9
1
[email protected], [email protected]
State University of Goiás, Br 153, 3105, Fazenda Barreiro do Meio, CP 459, CEP 75132-903, Anápolis, GO
(Brazil)
2
[email protected], 5 [email protected], 6 [email protected]
State University of Goiás, PPG Recursos Naturais do Cerrado, Br 153, 3105, Fazenda Barreiro do Meio, CP 459,
CEP 75132-903, Anápolis, GO (Brazil)
3
[email protected], 4 [email protected]
Federal University of Goiás, PPG Ecologia e Evolução, Campus Samambaia, Goiânia, GO (Brazil)
8
[email protected]
Federal University of Goiás, Campus Samambaia, Goiânia, GO (Brazil)
9
[email protected]
Institute of Marine Sciences, CSIC, Barcelona ES-08003 (Spain)
Introduction
The global number of papers published in different
areas has increased over the years (King, 2004).
Moreover, the science has experimented changes in
academic production scenarios, such as decreased
number of solo and increased team authors over the
years (Nabout et al., 2015). For many a researcher
the number of authors is one measure of
collaborations (Price, 1958).
In fact the collaboration has promoted strong
changes in science, and there are different reasons
for collaboration: increased publication quality
(Padial et al., 2010), and sharing costs and ideas
(Vermeulen, Parker & Penders, 2013).
For
Ecology, complex questions such as global climate
change, conservation plans of biodiversity among
others, have promoted collaboration between
scientists (Nabout et al., 2015). Moreover, there are
different possible levels of colaboration and an
important paper of Katz & Martin (1997) addresses
this issue. For these authors, collaboration is:
“Thus, a 'research collaboration' could be defined as
the working together of researchers to achieve the
common goal of producing new scientific
knowledge.” (Katz & Martin, 1997)
In general, the collaboration can be inter- or intraat different spatial scales (e.g. national or
international; intra or interinstitutional). This
variation indicates levels of collaboration.
Therefore, collaborations can occur between
researchers from the same institution, between
institutions of the same country and between
different countries (Katz & Martin, 1997). Several
methods have been proposed to measure the
collaboration and using different units (researchers,
institutes).
The aim of this study is to investigate the temporal
trends of number of authors in Ecology journals
between 1945 until 2014. Moreover, we will
investigate the influence of level of collaboration
(intra-institution - II; between-institutions - BI and
between-countries - BC) in scientific quality (i.e.
number of citation of paper). Our hypothesis is that
collaborative papers (BC) generate more citations.
Data
To assess the number of authors and level of
collaboration in Ecology papers, we selected all
journals listed in category “Ecology” in Web of
Science (www.isiknowledge.com, searched in
February of 2015). We selected for this study only
original articles (type of document), excluding
notes, reviews, errata and others. We adopted this
strategy to control the influence of type of
document in the number of authors (Padial et al.,
2010). The selection of papers considered all
periods available in the Web of Science database
(1945-2014). For collaboration analysis we
consider only recent papers (2012-2014). For each
paper, the following data were obtained: i) number
of authors, ii) number of citations, iii) year of
publication, and iv) the level of collaboration. For
this last variable, papers were categorized
according to the number of institutions of the
authors and co-authors and their location.
Therefore, authors affiliated with the same
610
institution were classified as intra-institutional
collaboration (II); between-institutional in same
country (BI) or between institution in different
countries (BC).
number of authors can also be an indication of the
level of collaboration.
Finally, our work shows an increase in the number
of multi-authored papers in Ecology. This is
probably due to the complexity of questions in
ecology which promotes collaboration between
researchers. In addition, international collaborations
have promoted papers with more citations (see
Glänzel, 2001). Thus, the reduction of travel costs
and the internet has allowed greater exchange
between countries. In addition, governmental
strategies can help in the exchange of researchers,
such as the Program Science Without Border in
Brazil. Thus, we encourage collaboration between
researchers seeking to improve the ecological
research of countries.
Temporal Trends of Number of Authors
We found a total of 333,214 articles published in
journals in the Ecology of Thomson-ISI between
the years 1945 and 2014. The investigation of the
number of authors per paper demonstrated a strong
decay in the numbers of single-authored papers. In
the early years, about 80% of papers in Ecology
were single-authored. In 2014 this value is 4.8%.
Statistical models suggest that in 2030 only 0.01%
of papers will be single-authored (see Nabout et al.,
2015). In addition, the number of papers with two
authors have also declined from the beginning of
the ’90s. Therefore, recently there has been
observed the increment in the number of papers
with four and five authors, which enhances the
tendency of multi-authored papers in Ecology. This
trend has been observed in many other areas of
science (Abt, 2007).
8
Mean
Mean±0.95 Conf. Interval
(A)
H=181.1; P<0.0001
Number of Citation
7
6
5
90
Number of Authors
1
2
3
4
5
6
7
8
9
10
80
% of Authors
70
60
50
4
II
BI
BC
Level of collaboration
Figure 2. Number of citations for each one of
level of collaboration.
40
Acknowledgments
Our work on Scientometrics and Ecology has been
continuously supported by different grants FAPEG,
CNPp and CAPES.
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References
Year
Abt, H.A. (2007). The future of single–authored papers.
Scientometrics, 73(3), 353–358.
Glänzel, W. (2001). National characteristics in
international scientific co-authorship relations.
Scientometrics, 51(1), 69-115.
Katz, S., & Martin, B.R. (1997). What is research
collaboration? Research Policy, 26(1): 1–18.
King, D.A. (2004). The scientific impact of nations.
Nature, 430, 311-316.
Nabout, J.C., Parreira, M.R., Teresa, F.B., Carneiro,
F.M., Cunha, H.F., Ondei, L.S., Caramori, S.S. &
Soares, T.N. (2015). Publish (in a group) or perish
(alone): the trend from single- to multi-authorship in
biological papers. Scientometrics, 102, 357-364.
Padial A.A., Nabout, J.C., Siqueira T., Bini, L.M., DinizFilho, J.A.F. (2010). Weak evidence for determinants
of citation frequency in ecological articles.
Scientometrics, 85,1-12.
Price, D.J.S. (1963). Little Science, Big Science. New
York: Columbia University Press.
Vermeulen, N., Parker, J. N., & Penders, B. (2013).
Understanding life together: A brief history of
collaboration in biology. Endeavour, 37(3), 162–171.
Figure 1. Temporal trends of the proportion of
number of authors in Ecology Papers.
Levels of Collaboration
The papers of the years 2011, 2012 and 2013
exclusively of Ecology, totaling 10,457, were
classified according to the level of collaboration (II,
BI or BC). The Kruskal-Wallis (H) one-way
analysis of variance by ranks was performed to
assess if the number of citations is affected by the
level of collaboration. We found a strong
statistically significant difference (P<0.01),
suggesting that collaborative papers written by
authors from different countries received more
citations Figure 2). This result reinforces the
importance (and a recent trend) of international
collaboration.
Using the same analysis we observed that the
number of authors differs significantly between the
levels of collaboration. In other words, BC papers
have higher number of authors than those of SI and
BI papers (H = 1868, P <0.001). Therefore, the
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