The science and engineering base is a key source of knowledge for the development and use of Info... more The science and engineering base is a key source of knowledge for the development and use of Information and Communication Technologies (ICTs). In order to be able to effectively describe and monitor worldwide scientific activity related to ICTs, it is important to be able to provide reliable macro-level statistics of this knowledge base. International bibliographic databases and related bibliometric indicators together provide an analytical framework and appropriate measures to cover both the 'supply side'-research capabilities and outputs-and 'demand side'-collaboration, diffusion and citation impact-related to the ICT research. This paper presents results of such a bibliometric study describing macro-level features of this ICT knowledge base. The data were retrieved from a specially developed CWTS 1CTDatabase which provides a broad-scope worldwide coverage of ICT-relevant research papers published in highquality international scientific and technical journals. The crosscountry comparison focuses on the level of scientific output and cooperation patterns of the most actively publishing nations with a focus on the three Triad zones-the European Union, the USA and Japan. The significance of the ICT science and engineering base The revolution in Information and Communication Technologies (ICTs) is changing the nature of many economic sectors, and indeed of whole societies, around the world. Computers and telecommunications equipment, and the ever wider distribution of ICT products and services, which are now driving and enabling many changes in the cultural, educational, organizational and economic structures. 1,2 Internet, mobile phones, video services, electronic commerce techniques, multimedia CD/ROM databases, traffic control systems and many other iCT-related facilities, have given a strong impetus to the process of codi~lcation, dissemination and use of information. ICTs thus contribute significantly to the emerging 'Information Society' and related
... For awareness we also collected the references. After transferring the data from the PC to th... more ... For awareness we also collected the references. After transferring the data from the PC to the main-frame, we processed these with help of 'Statistical Analysis System' (SAS), a software package developed by SAS Institute Inc., Cary N~.C. (USA). ...
... But the impact of neural network research on neurophysiology is small. The simplified models ... more ... But the impact of neural network research on neurophysiology is small. The simplified models are still far remote from biological reality. ... In this case, neural network research, we applied a 'two-step co-word analysis'. Scientometric$ 26 (1993) 177 Page 10. A.FJ. ...
This paper reports on a quantitative analytical methodology which deals with perceptions of scien... more This paper reports on a quantitative analytical methodology which deals with perceptions of scientific experts regarding the intellectual shape and contents ('cognitive structure') of their scientific domain. This study examines the method's utility for studying expert views in general, and, more specifically, its strengths and weaknesses as a tool for improving validation studies of bibliometric maps involving subject experts. The main premise is that expert views are based on their internal knowledge structures ('mental schemes') of which relevant features can be captured in quantitative data. This approach allows a rigorous and systematic way of studying mental schemes across subject experts. Spatial representations of their data ('mental maps') provide insight in properties underlying those knowledge structures. Data from different experts are reconciled to construct a 'common' mental map which displays a group view. This study includes a test to establish the validity of individual mental maps and common mental maps. The methodology is applied to the views of 14 researchers in the field of neural network research and related areas. Key-findings are: (i) mental maps can provide valid representations of expert mental schemes, (ii) experts sharing the same subject field are more likely to share views, (iii) expert judgements of bibliometric maps are affected by the structure of their own mental schemes, as well as (iv) by their views regarding the utility of those maps, and (v) common mental maps and a bibliometric co-word map based on the same set of items differ significantly, showing a resemblance on main features only. Validation of bibliometric maps Over the last two decades scientometricians have used data-reduction tools to study complex relational structures within the science system. Some of those analytical techniques provide spatial representations depicting the main findings in an easily comprehensible manner. Those 'maps of the sciencescape' are mostly derived from the analysis of quantitative literature-based (bibliometric) data and are mainly employed for displaying knowledge ('cognitive') structures within scientific areas. 1 Their input consists of quantitative data referring to the degree of relatedness among research publications. For example, cross-reference frequencies (co-citations), co
This paper presents a selection of results of a comprehensive quantitative, research literature-b... more This paper presents a selection of results of a comprehensive quantitative, research literature-based study of Dutch energy research. The primary goal of this paper is to provide an overview of what bibliometric data from ISI and non-ISI databases may offer to describe the state of affairs in a scientific field. It illustrates the added value of combining bibliometric indicators of publication output, international visibility, international co-operation, and interdisciplinarity in a study of nuclear energy research in the 1980's when its budget decreased dramatically.
This article presents results of a study on the applicability of journal mapping of knowledge dom... more This article presents results of a study on the applicability of journal mapping of knowledge domains beyond the databases produced by the Institute for Scientific Information (ISI). The utility and validity of this generalisation is discussed with an emphasis on its added value in comparison to traditional ISI-based journal maps, i.e. those restricted to (predominantly English-language) ISI-covered journals, and journal-to-journal
The LEXIMAPPE method and Multidimensional Scaling (MDS) are discussed as methods to visualize (ma... more The LEXIMAPPE method and Multidimensional Scaling (MDS) are discussed as methods to visualize (map) characteristics of structures of word-occurrence (co-word) relations. Utilization of MDS is proposed as an alternative mapping method able to circumvent problematic features of LEXIMAPPE maps of the total co-word structure. A comparison of both methods on the same real-life co-word matrix demonstrates topological advantages of an
A growing science policy interest in international scientific collaboration has brought about a m... more 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.
ABSTRACT R&D collaboration between industry and universities has been become an academic ... more ABSTRACT R&D collaboration between industry and universities has been become an academic research topic in its own right. Public private cooperation is high on many policy agenda's nowadays, especially with regard to science-based technological innovation. Nonetheless, there is still a surprising lack of quantitative data and large-scale systematic measurement. This article presents a series of empirical studies on private-public research cooperation as measured by jointly authored research articles published in international scientific and technical journals. The tens of thousands of public-private co-publications (PPCs) that appear each year in the open scientific literature contain a wealth of information on research cooperation patterns and trends. The institutional address of each co-authoring researcher and the geographic location of their affiliation, provide data for internationally comparative statistics. These macrolevel studies, introducing aggregate-level PPC statistics for countries and European regions, examine pros and cons of PPC analytics to assess the geography of public-private research cooperation. A critical discussion of selected findings is framed within the evaluative context of European Commission policy reports, which have started to apply PPC-based metrics and performance indicators for strategic analysis of science and innovation systems. The conclusions point out that those applications should take into account the varying PPC propensities of research fields and related industrial sectors. Moreover, PPC data seem more appropriate for examining and understanding cooperation patterns at the level of city agglomerations (NUTS3 regions) within Europe than provinces or other aggregates at the NUTS2 level.
Journal of the American Society for Information Science and Technology, 2012
The Leiden Ranking 2011/2012 is a ranking of universities based on bibliometric indicators of pub... more 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 university's highly cited publications, (2) indicators based on fractional rather than full cou...
The last decades have seen an increasing utilization of graphical representations of aspects of s... more The last decades have seen an increasing utilization of graphical representations of aspects of science. These "maps" are mainly used to depict the underlying relational structures of publications, or publishing entities, within the science and technology system. To this end, the maps generally draw on only one source of bibliometric (i.e., literature-based quantita tive) data—mostly citations or keywords. These information items will necessarily descnbe only one facet of the (intellect ual and/or social) structure of science. We argue that in order to obtain a more complete description of the common underly ing structure one requires the incorporation of more sources of (bibliometric) data. We discuss the statistical model INDSCAL that combines multiple sources (e.g., citations, keywords, sub ject classificanon codes). This model yields an integrated multi-dimensional representation of the relational structure of a set of scientific entities common to all sources. The uti...
Using a combination of two exploratory macro-level analyses this study investigates Dutch industr... more Using a combination of two exploratory macro-level analyses this study investigates Dutch industry's research output in a range of scientific fields as published in international journals in 1993–94. It focuses on four specific scientific fields that are relevant to Dutch industry: materials science, catalysis research, chemical process technology, and environmental sciences. The results indicate that international publication activity occurs within smaller companies as well as the large R&D-intensive (multinational) firms. Industry is more likely to co-author scientific articles with public-sector researchers if the research field is peripheral to industry in terms of strategic interests and core competence. The four selected fields demonstrate noticeably different (co-)publication profiles of industry, reflecting the scientific input characteristics of those fields. Copyright , Beech Tree Publishing.
This paper presents findings of a study that discloses key features of the Dutch R&am... more This paper presents findings of a study that discloses key features of the Dutch R&D network in the area of catalysis, a sub-domain of industrial-relevant chemistry. The input comprises empirical data on collaborative research publications, informal network ties, and formal R&D linkages. The study aimed at identifying all public and private sector research organisations involved in the network, characterising their
This paper introduces a citation-based metholodology to characterize and measure the magnitude an... more This paper introduces a citation-based metholodology to characterize and measure the magnitude and intensity of knowledge flows and knowledge spillovers from the public research sector to basic and strategic research in the private sector. We present results derived from an interrelated series of statistical analyses based on Private-to-Public Citations (PrPuCs) within reference lists of the research articles produced by industrial researchers during the years 1996-2003.
Today's theories and models on innovation stress the importance of scientific capabilities and sc... more Today's theories and models on innovation stress the importance of scientific capabilities and science-technology proximity, especially in new emerging fields of economic activity. In this contribution we examine the relationship between national scientific capabilities, the science intensity of technology and technological performance within six promising industrial fields. Our findings reveal that national technological performance is positively associated with scientific capabilities. Countries performing better on a technological level are characterized both by larger numbers of publications and by numbers of involved institutions that exceed average expected values. The latter observation holds for both companies and knowledge generating institutes actively involved in scientific activities. As such, our findings seem to suggest beneficial effects of scientific capabilities shouldered by a multitude of organizations. In addition, higher numbers of patent activity coincide with higher levels of science intensity pointing out the relevance of science 'proximity' when developing technology in newer, emerging fields. Limitations and directions for further research are discussed.
This paper examines general characteristics of African science from a quantitative ‘scientometric... more 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
This study analyses the changing effect of physical distance and territorial borders (regional, n... more This study analyses the changing effect of physical distance and territorial borders (regional, national, language) on the intensity of research collaboration across European regions. Using data on all co-publications between 313 regions in 33 European countries for the period ...
The science and engineering base is a key source of knowledge for the development and use of Info... more The science and engineering base is a key source of knowledge for the development and use of Information and Communication Technologies (ICTs). In order to be able to effectively describe and monitor worldwide scientific activity related to ICTs, it is important to be able to provide reliable macro-level statistics of this knowledge base. International bibliographic databases and related bibliometric indicators together provide an analytical framework and appropriate measures to cover both the 'supply side'-research capabilities and outputs-and 'demand side'-collaboration, diffusion and citation impact-related to the ICT research. This paper presents results of such a bibliometric study describing macro-level features of this ICT knowledge base. The data were retrieved from a specially developed CWTS 1CTDatabase which provides a broad-scope worldwide coverage of ICT-relevant research papers published in highquality international scientific and technical journals. The crosscountry comparison focuses on the level of scientific output and cooperation patterns of the most actively publishing nations with a focus on the three Triad zones-the European Union, the USA and Japan. The significance of the ICT science and engineering base The revolution in Information and Communication Technologies (ICTs) is changing the nature of many economic sectors, and indeed of whole societies, around the world. Computers and telecommunications equipment, and the ever wider distribution of ICT products and services, which are now driving and enabling many changes in the cultural, educational, organizational and economic structures. 1,2 Internet, mobile phones, video services, electronic commerce techniques, multimedia CD/ROM databases, traffic control systems and many other iCT-related facilities, have given a strong impetus to the process of codi~lcation, dissemination and use of information. ICTs thus contribute significantly to the emerging 'Information Society' and related
... For awareness we also collected the references. After transferring the data from the PC to th... more ... For awareness we also collected the references. After transferring the data from the PC to the main-frame, we processed these with help of 'Statistical Analysis System' (SAS), a software package developed by SAS Institute Inc., Cary N~.C. (USA). ...
... But the impact of neural network research on neurophysiology is small. The simplified models ... more ... But the impact of neural network research on neurophysiology is small. The simplified models are still far remote from biological reality. ... In this case, neural network research, we applied a 'two-step co-word analysis'. Scientometric$ 26 (1993) 177 Page 10. A.FJ. ...
This paper reports on a quantitative analytical methodology which deals with perceptions of scien... more This paper reports on a quantitative analytical methodology which deals with perceptions of scientific experts regarding the intellectual shape and contents ('cognitive structure') of their scientific domain. This study examines the method's utility for studying expert views in general, and, more specifically, its strengths and weaknesses as a tool for improving validation studies of bibliometric maps involving subject experts. The main premise is that expert views are based on their internal knowledge structures ('mental schemes') of which relevant features can be captured in quantitative data. This approach allows a rigorous and systematic way of studying mental schemes across subject experts. Spatial representations of their data ('mental maps') provide insight in properties underlying those knowledge structures. Data from different experts are reconciled to construct a 'common' mental map which displays a group view. This study includes a test to establish the validity of individual mental maps and common mental maps. The methodology is applied to the views of 14 researchers in the field of neural network research and related areas. Key-findings are: (i) mental maps can provide valid representations of expert mental schemes, (ii) experts sharing the same subject field are more likely to share views, (iii) expert judgements of bibliometric maps are affected by the structure of their own mental schemes, as well as (iv) by their views regarding the utility of those maps, and (v) common mental maps and a bibliometric co-word map based on the same set of items differ significantly, showing a resemblance on main features only. Validation of bibliometric maps Over the last two decades scientometricians have used data-reduction tools to study complex relational structures within the science system. Some of those analytical techniques provide spatial representations depicting the main findings in an easily comprehensible manner. Those 'maps of the sciencescape' are mostly derived from the analysis of quantitative literature-based (bibliometric) data and are mainly employed for displaying knowledge ('cognitive') structures within scientific areas. 1 Their input consists of quantitative data referring to the degree of relatedness among research publications. For example, cross-reference frequencies (co-citations), co
This paper presents a selection of results of a comprehensive quantitative, research literature-b... more This paper presents a selection of results of a comprehensive quantitative, research literature-based study of Dutch energy research. The primary goal of this paper is to provide an overview of what bibliometric data from ISI and non-ISI databases may offer to describe the state of affairs in a scientific field. It illustrates the added value of combining bibliometric indicators of publication output, international visibility, international co-operation, and interdisciplinarity in a study of nuclear energy research in the 1980's when its budget decreased dramatically.
This article presents results of a study on the applicability of journal mapping of knowledge dom... more This article presents results of a study on the applicability of journal mapping of knowledge domains beyond the databases produced by the Institute for Scientific Information (ISI). The utility and validity of this generalisation is discussed with an emphasis on its added value in comparison to traditional ISI-based journal maps, i.e. those restricted to (predominantly English-language) ISI-covered journals, and journal-to-journal
The LEXIMAPPE method and Multidimensional Scaling (MDS) are discussed as methods to visualize (ma... more The LEXIMAPPE method and Multidimensional Scaling (MDS) are discussed as methods to visualize (map) characteristics of structures of word-occurrence (co-word) relations. Utilization of MDS is proposed as an alternative mapping method able to circumvent problematic features of LEXIMAPPE maps of the total co-word structure. A comparison of both methods on the same real-life co-word matrix demonstrates topological advantages of an
A growing science policy interest in international scientific collaboration has brought about a m... more 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.
ABSTRACT R&D collaboration between industry and universities has been become an academic ... more ABSTRACT R&D collaboration between industry and universities has been become an academic research topic in its own right. Public private cooperation is high on many policy agenda's nowadays, especially with regard to science-based technological innovation. Nonetheless, there is still a surprising lack of quantitative data and large-scale systematic measurement. This article presents a series of empirical studies on private-public research cooperation as measured by jointly authored research articles published in international scientific and technical journals. The tens of thousands of public-private co-publications (PPCs) that appear each year in the open scientific literature contain a wealth of information on research cooperation patterns and trends. The institutional address of each co-authoring researcher and the geographic location of their affiliation, provide data for internationally comparative statistics. These macrolevel studies, introducing aggregate-level PPC statistics for countries and European regions, examine pros and cons of PPC analytics to assess the geography of public-private research cooperation. A critical discussion of selected findings is framed within the evaluative context of European Commission policy reports, which have started to apply PPC-based metrics and performance indicators for strategic analysis of science and innovation systems. The conclusions point out that those applications should take into account the varying PPC propensities of research fields and related industrial sectors. Moreover, PPC data seem more appropriate for examining and understanding cooperation patterns at the level of city agglomerations (NUTS3 regions) within Europe than provinces or other aggregates at the NUTS2 level.
Journal of the American Society for Information Science and Technology, 2012
The Leiden Ranking 2011/2012 is a ranking of universities based on bibliometric indicators of pub... more 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 university's highly cited publications, (2) indicators based on fractional rather than full cou...
The last decades have seen an increasing utilization of graphical representations of aspects of s... more The last decades have seen an increasing utilization of graphical representations of aspects of science. These "maps" are mainly used to depict the underlying relational structures of publications, or publishing entities, within the science and technology system. To this end, the maps generally draw on only one source of bibliometric (i.e., literature-based quantita tive) data—mostly citations or keywords. These information items will necessarily descnbe only one facet of the (intellect ual and/or social) structure of science. We argue that in order to obtain a more complete description of the common underly ing structure one requires the incorporation of more sources of (bibliometric) data. We discuss the statistical model INDSCAL that combines multiple sources (e.g., citations, keywords, sub ject classificanon codes). This model yields an integrated multi-dimensional representation of the relational structure of a set of scientific entities common to all sources. The uti...
Using a combination of two exploratory macro-level analyses this study investigates Dutch industr... more Using a combination of two exploratory macro-level analyses this study investigates Dutch industry's research output in a range of scientific fields as published in international journals in 1993–94. It focuses on four specific scientific fields that are relevant to Dutch industry: materials science, catalysis research, chemical process technology, and environmental sciences. The results indicate that international publication activity occurs within smaller companies as well as the large R&D-intensive (multinational) firms. Industry is more likely to co-author scientific articles with public-sector researchers if the research field is peripheral to industry in terms of strategic interests and core competence. The four selected fields demonstrate noticeably different (co-)publication profiles of industry, reflecting the scientific input characteristics of those fields. Copyright , Beech Tree Publishing.
This paper presents findings of a study that discloses key features of the Dutch R&am... more This paper presents findings of a study that discloses key features of the Dutch R&D network in the area of catalysis, a sub-domain of industrial-relevant chemistry. The input comprises empirical data on collaborative research publications, informal network ties, and formal R&D linkages. The study aimed at identifying all public and private sector research organisations involved in the network, characterising their
This paper introduces a citation-based metholodology to characterize and measure the magnitude an... more This paper introduces a citation-based metholodology to characterize and measure the magnitude and intensity of knowledge flows and knowledge spillovers from the public research sector to basic and strategic research in the private sector. We present results derived from an interrelated series of statistical analyses based on Private-to-Public Citations (PrPuCs) within reference lists of the research articles produced by industrial researchers during the years 1996-2003.
Today's theories and models on innovation stress the importance of scientific capabilities and sc... more Today's theories and models on innovation stress the importance of scientific capabilities and science-technology proximity, especially in new emerging fields of economic activity. In this contribution we examine the relationship between national scientific capabilities, the science intensity of technology and technological performance within six promising industrial fields. Our findings reveal that national technological performance is positively associated with scientific capabilities. Countries performing better on a technological level are characterized both by larger numbers of publications and by numbers of involved institutions that exceed average expected values. The latter observation holds for both companies and knowledge generating institutes actively involved in scientific activities. As such, our findings seem to suggest beneficial effects of scientific capabilities shouldered by a multitude of organizations. In addition, higher numbers of patent activity coincide with higher levels of science intensity pointing out the relevance of science 'proximity' when developing technology in newer, emerging fields. Limitations and directions for further research are discussed.
This paper examines general characteristics of African science from a quantitative ‘scientometric... more 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
This study analyses the changing effect of physical distance and territorial borders (regional, n... more This study analyses the changing effect of physical distance and territorial borders (regional, national, language) on the intensity of research collaboration across European regions. Using data on all co-publications between 313 regions in 33 European countries for the period ...
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