3,247 research outputs found
International Collaboration in Science and the Formation of a Core Group
International collaboration as measured by co-authorship relations on
refereed papers grew linearly from 1990 to 2005 in terms of the number of
papers, but exponentially in terms of the number of international addresses.
This confirms Persson et al.'s (2004) hypothesis of an inflation in
international collaboration. Patterns in international collaboration in science
can be considered as network effects, since there is no political institution
mediating relationships at that level except for the initiatives of the
European Commission. During the period 2000-2005, the network of global
collaborations appears to have reinforced the formation of a core group of
fourteen most cooperative countries. This core group can be expected to use
knowledge from the global network with great efficiency, since these countries
have strong national systems. Countries at the periphery may be disadvantaged
by the increased strength of the core
An Integrated Impact Indicator (I3): A New Definition of "Impact" with Policy Relevance
Allocation of research funding, as well as promotion and tenure decisions,
are increasingly made using indicators and impact factors drawn from citations
to published work. A debate among scientometricians about proper normalization
of citation counts has resolved with the creation of an Integrated Impact
Indicator (I3) that solves a number of problems found among previously used
indicators. The I3 applies non-parametric statistics using percentiles,
allowing highly-cited papers to be weighted more than less-cited ones. It
further allows unbundling of venues (i.e., journals or databases) at the
article level. Measures at the article level can be re-aggregated in terms of
units of evaluation. At the venue level, the I3 creates a properly weighted
alternative to the journal impact factor. I3 has the added advantage of
enabling and quantifying classifications such as the six percentile rank
classes used by the National Science Board's Science & Engineering Indicators.Comment: Research Evaluation (in press
The geography of references in elite articles: What countries contribute to the archives of knowledge
This study is intended to find an answer for the question on which national
"shoulders" the worldwide top-level research stands. Traditionally, national
scientific standings are evaluated in terms of the number of citations to their
papers. We raise a different question: instead of analyzing the citations to
the countries' articles (the forward view), we examine referenced publications
from specific countries cited in the most elite publications (the
backward-citing-view). "Elite publications" are operationalized as the top-1%
most-highly cited articles. Using the articles published during the years 2004
to 2013, we examine the research referenced in these works. Our results confirm
the well-known fact that China has emerged to become a major player in science.
However, China still belongs to the low contributors when countries are ranked
as contributors to the cited references in top-1% articles. Using this
perspective, the results do not point to a decreasing trend for the USA; in
fact, the USA exceeds expectations (compared to its publication share) in terms
of contributions to cited references in the top-1% articles. Switzerland,
Sweden, and the Netherlands also are shown at the top of the list. However, the
results for Germany are lower than statistically expected
Betweenness and Diversity in Journal Citation Networks as Measures of Interdisciplinarity -- A Tribute to Eugene Garfield --
Journals were central to Eugene Garfield's research interests. Among other
things, journals are considered as units of analysis for bibliographic
databases such as the Web of Science (WoS) and Scopus. In addition to
disciplinary classifications of journals, journal citation patterns span
networks across boundaries to variable extents. Using betweenness centrality
(BC) and diversity, we elaborate on the question of how to distinguish and rank
journals in terms of interdisciplinarity. Interdisciplinarity, however, is
difficult to operationalize in the absence of an operational definition of
disciplines, the diversity of a unit of analysis is sample-dependent. BC can be
considered as a measure of multi-disciplinarity. Diversity of co-citation in a
citing document has been considered as an indicator of knowledge integration,
but an author can also generate trans-disciplinary--that is,
non-disciplined--variation by citing sources from other disciplines. Diversity
in the bibliographic coupling among citing documents can analogously be
considered as diffusion of knowledge across disciplines. Because the citation
networks in the cited direction reflect both structure and variation, diversity
in this direction is perhaps the best available measure of interdisciplinarity
at the journal level. Furthermore, diversity is based on a summation and can
therefore be decomposed, differences among (sub)sets can be tested for
statistical significance. In an appendix, a general-purpose routine for
measuring diversity in networks is provided
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