Robert J. W. Tijssen

Language biases in the coverage of the Science Citation Index and its consequencesfor international comparisons of national research performance

Empirical evidence presented in this paper shows that the utmost care must be taken ininterpreting bibliometric data in a comparative evaluation of national research systems. From theresults of recent studies, the authors conclude that the value of impact indicators of researchactivities at the level of an institution or a country strongly depend upon whether one includes orexcludes research publications in SCI covered journals written in other languages than in English.Additional material was gathered to show the distribution of SCI papers among publicationlanguages. Finally, the authors make suggestions for further research on how to deal with this typeof problems in future national research performance studies.

The measurement of international scientific collaboration

A growing science policy interest in international scientific collaboration has brought about a multitude of studies which attempt to measure the extent of international scientific collaboration between countries and to explore intercountry collaborative networks. This paper attempts to clarify the methodology that is being used or can be used for this purpose and discusses the adequacy of the methods. The paper concludes that, in an analysis of collaborative links, it is essential to use both absolute and relative measures. The latter normalize differences in country size. Each yields a different type of information. Absolute measures yield an answer to questions such as which countries are central in the international network of science, whether collaborative links reveal a centre — periphery relationship, and which countries are the most important collaborative partners of another country. Relative measures provide answers to questions of the intensity of collaborative links.

The Leiden ranking 2011/2012: Data collection, indicators, and interpretation

The Leiden Ranking 2011/2012 is a ranking of universities based on bibliometric indicators of publication output, citation impact, and scientific collaboration. The ranking includes 500 major universities from 41 different countries. This paper provides an extensive discussion of the Leiden Ranking 2011/2012. The ranking is compared with other global university rankings, in particular the Academic Ranking of World Universities (commonly known as the Shanghai Ranking) and the Times Higher Education World University Rankings. The comparison focuses on the methodological choices underlying the different rankings. Also, a detailed description is offered of the data collection methodology of the Leiden Ranking 2011/2012 and of the indicators used in the ranking. Various innovations in the Leiden Ranking 2011/2012 are presented. These innovations include (1) an indicator based on counting a universitys highly cited publications, (2) indicators based on fractional rather than full counting of collaborative publications, (3) the possibility of excluding non-English language publications, and (4) the use of stability intervals. Finally, some comments are made on the interpretation of the ranking and a number of limitations of the ranking are pointed out.

Global and domestic utilization of industrial relevant science: patent citation analysis of science–technology interactions and knowledge flows

Abstract The development of science-based technologies may draw heavily on codified and tacit outputs from both domestic research bases and foreign sources. Having a view of the scientific underpinnings of these technical innovations and related knowledge diffusion and utilization processes, especially those concerning public-financed basic research, is of major importance to policymakers nowadays. Some of those scientific and technical inputs are pivotal to technical inventions and are acknowledged as such by explicit references (“citations”) to related research papers in the reference list on the corresponding patents. This case study deals with citations to Dutch-authored research papers on USPTO patents granted during the period 1987–1996. Results of the citation analysis reveal several important features of contributions made by the Dutch science base to Dutch-invented and/or foreign-invented patents such as (1) a marked overall increase of patent citations to Dutch research papers, and (2) significant differences between domestic and foreign citation patterns where (3) domestic citation links are dominated by author–inventor self-citations and patents originating from the large R&D-intensive multinational firms such as Philips. These findings provide new empirical evidence that patent citation analysis produces systemic quantitative data providing strategic background information regarding nation-specific and sector-specific factors in domestic and cross-border science–technology linkages and knowledge flows.

Chinese researchers returning home: Impacts of international mobility on research collaboration and scientific productivity

The aim of this study is to contribute to the debate on the relationship between scientific mobility and international collaboration. This case study deals with leading Chinese researchers in the field of plant molecular life sciences who returned to their home country. A correlation analysis of their mobility history, publication output, and international co-publication data, shows the relationship between scientific output, levels of international collaboration and various individual characteristics of returned researchers. The outcome of the analysis suggests that while host countries may loose human capital when Chinese scientists return home, the so-called “return brain drain”, they may also gain in terms of scientific linkages within this rapidly emerging and globalizing research field.

A quantitative assessment of interdisciplinary structures in science and technology: Co-classification analysis of energy research

Abstract The wide diversity in subject matter and volume of research publications of large multidisciplinary areas often presents an insurmountable barrier in obtaining a comprehensive overview of its internal (“intellectual”) structure. In this article it is shown that a systematic, quantitative examination of the contents of an areas research publications offers an empirical solution for this problem. This “co-classification analysis” is based on the network of interdisciplinary links between research fields contributing to such an area, as manifest in the co-occurrence of different subject-classification headings assigned to research publications. The analysis yields quantitative measures of: (1) the level of interdisciplinarity in contributing research fields; (2) the strength of interdisciplinary relations between these fields, as well as (3) graphical representations (“maps”) of the interdisciplinary structure in single fields, as well as the area as a whole. Capabilities and limitations of this methodology, as an aid in research policy studies, are discussed by way of a Dutch science-policy-driven application to the area of energy research. Results are presented concerning the worldwide interdisciplinary structure of energy research, and the structure in Dutch publications on research sources of renewable energy. Findings of a subsequent validation study amongst Dutch scientists, R&D managers, and S&T policy makers support our assertion that the method is useful for certain analytical and descriptive purposes, but also point out limits in its range of application.

Africa's contribution to the worldwide research literature: New analytical perspectives, trends, and performance indicators

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.

The neural net of neural network research

In this paper we discuss the limits and potentials of bibliometric mapping based on a specific co-word analysis. The subject area is neural network research. Our approach is a ‘simulation’ of expert assessment by offering the reader a narrative of the field which can be used as background information when ‘reading’ the bibliometric maps. The central issue in the applicability of bibliometric maps is whether these maps may supply ‘additional intelligence’ to users. In other words, whether such a bibliometric tool has an epistemological value, in the sense that it ecriches existing knowledge by supplying ‘unexpected’ relations between specific ‘pieces’ of knowledge (‘synthetic value’) or by supplying ‘unexpected’ problems (‘creative value’). We argue that sophisticated bibliometric mapping techniques are indeed valuable for open new avenues to study science as a self-organizing system in the form of a ‘neural network like’ structure of which the bibliometric map is a first-order aproximation. In that sense, this paper deals with the ‘neural net of neural network research’ as our bibliometric techniques in fact mimic a connectionistic approach.

Science dependence of technologies: evidence from inventions and their inventors

Abstract Articulating a compelling economic rationale to justify investments in research—by definition furthest removed from direct, immediate economic benefit—is perhaps one of chief challenges of R&D managers, policy makers and science analysts in the years ahead. Although several innovation studies and surveys have provided some convincing empirical evidence of impacts and benefits of research to technical progress, there is still an urgent need for comprehensive models, reliable data and analytical tools to describe and monitor links between R&D and industrial innovation in more detail. As for the role of scientific and engineering research in the innovation process, this paper reports on the findings of a novel methodology to increase our understanding of the contribution of research efforts to successful technical inventions. The approach is based on a nation-wide mail survey amongst inventors working in the corporate sector and the public research sector in The Netherlands. The inventors’ inside information regarding their patented inventions—and related technological innovations on the market—provided a range of quantitative data on the importance of the underpinning research activities. Statistical models attempting to explain the degree of “science dependence” of the inventions identify a range of relevant variables, covering the inventor’s own capabilities and previous R&D achievements, external information sources, as well as the inventor’s R&D environment in general. Some 20% of the private sector innovations turned out to be (partially) based on public sector research. Furthermore, citations in patents referring to basic research literature were found to be invalid indictors of a technology’s science dependence.

Interdisciplinary dynamics of modern science: analysis of cross-disciplinary citation flows

The references in research papers provide empirical data on knowledge flows within and between scientific disciplines. Many citations refer to papers that are published in scientific journals covering adjacent scientific disciplines. We have used this information source to explore — at the global level — the extent to which disciplines are interrelated through these cross-disciplinary citation links. In this paper we describe the main features of the bibliometric methodology. The first results of this study provide new macro-level data on the interdisciplinarity of modern science and identify a few disciplines, such as meteorology and atmospheric sciences, in which research has become noticeably more interdisciplinary. Copyright , Beech Tree Publishing.