Authors:Rodrigo Costas, Thed N. van Leeuwen, and Anthony F. J. van Raan
analysis of the obsolescence (Line 1993 ) or “durability” of knowledge (Tahai and Rigsby 1998 ). The analysis of the ageing of scientific production has been frequently addressed in bibliometric literature (Aversa 1985 ; Glänzel and Schoepflin 1995
This paper examines general characteristics of African science from a quantitative ‘scientometric’ perspective. More specifically,
that of research outputs of Africa-based authors published in the scientific literature during the years 1980–2004, either
within the international journals representing ‘mainstream’ science, or within national and regional journals reflecting ‘indigenous
science’. As for the international journals, the findings derived from Thomson Scientific’s Citation Indexes show that while
Africa’s share in worldwide science has steadily declined, the share of international co-publications has increased very significantly,
whereas low levels of international citation impact persist. A case study of South African journals reveals the existence
of several journals that are not processed for these international databases but nonetheless show a distinctive citation impact
on international research communities.
, however, tests of the second hypothesis are inconclusive.
Below I present the theory, describe the data and methods, and present the results. A discussion describes contributions to the literature as well as limitations of this study, and a
Authors:Ludo Waltman, Nees Jan van Eck, Thed N. van Leeuwen, Martijn S. Visser, and Anthony F. J. van Raan
excellent research with a high degree of accuracy. This is a strong assumption. There is an extensive literature which indicates that peer review, just like citation analysis, has significant limitations (for an overview, see Bornmann 2011 ). For instance
Authors:Thomas Gurney, Edwin Horlings, and Peter van den Besselaar
combinations of indicators used.
The paper is structured as follows. In the next section, we review the literature on the current disambiguation methods being employed, with an emphasis on methods that mix both computer science, and sociological and
I use the normalised Herfindahl–Hirschman Index (HHI) to measure concentration (Herfindahl 1951 ; Hirschman 1964 ). 3 While not new (Cox and Chung 1991 ; Rubin and Chang 2003 ), this is not common in the scientometric literature. 4
available a strongly reduced version of the database (ICHMP lite) online, adapted for browse purpose. 4
In order to answer the aforementioned questions the subject literature may be useful, but only to some extent. Apart from numerous works (McCrank
this second purpose are less common in the literature but equally attractive, since they enable us to delve into different aspects of the behaviour of researchers such as their collaboration habits and interactions, their different roles in the
Authors:Joanna Wolszczak-Derlacz and Aleksandra Parteka
The development of nonparametric methods such as Data Envelopment Analysis (DEA), Free Disposal Hull (FDH) and others (e.g. Malmquist indices) have resulted in burgeoning literature on efficiency assessments of
of a data source. The ISI Web of Science is a popular service, since it offers highly structured and consistent data. Its coverage of scientific literature is, however, very limited in comparison to Google Scholar (Meho and Yang 2007 ). I therefore