Evidence for the invalidity of the Bradford law for the single scientist

On the basis of a previously proposed method using meta-informations accumulating during SDI from an international system of the INIS-type, it is investigated, how the scientific journal rank distribution of a research institution, for which the Bradford law is valid, is composed of the single scientists' journal distributions. In this transition from a macroscopic into a microscopic field of scientific communication evidence was found for the invalidity of the Bradford law for the journal rank distribution of a single scientist. This effect seems to confirm a fundamental qualitative difference of both fields of scientific communication.     

National research contributions: A case study on Finnish biomedical research

The long-term influence and contribution of research can be evaluated relatively reliably by bibliometric citation analysis. Previously, productivity of nations has been estimated by using either the number of published articles or journal impact factors and/or citation data. These studies show certain trends, but detailed analysis is not possible due to the assumption that all articles in a journal were equally cited. Here we describe the first comprehensive, longterm, nationwide analysis of scientific performance. We studied the lifetime research output of 748 Finnish principal investigators in biomedicine during the years 1966–2000, analysed national trends, and made a comparison with international research production. Our results indicate that analyses of the scientific contribution of persons, disciplines, or nations should be based on actual publication and citation counts rather than on derived information like impact factors. 51% of the principal investigators have published altogether 75% of the articles; however, the whole scientific community has contributed to the growth of biomedical research in Finland since the Second World War.     

‘Triad’ or ‘tetrad’? On global changes in a dynamic world

The US-EU race for world leadership in science and technology has become the favourite subject of recent studies. Studies issued by the European Commission reported the increase of the European share in the world’s scientific production and announced world leadership of the EU in scientific output at the end of the last century. In order to be able to monitor those types of global changes, the present study is based on the 15-year period 1991–2005. A set of bibliometric and technometric indicators is used to analyse activity and impact patterns in science and technology output. This set comprises publication output indicators such as (1) the share in the world total, (2) subject-based publication profiles, (3) citation-based indicators like journal-and subject-normalised mean citation rates, (4) international co-publications and their impact as well as (5) patent indicators and publication-patent citation links (both directions). The evolution of national bibliometric profiles, ‘scientific weight’ and science-technology linkage patterns are discussed as well. The authors show, using the mirror of science and technology indicators, that the triad model does no longer hold in the 21^st century. China is challenging the leading sciento-economic powers and the time is approaching when this country will represent the world’s second largest potential in science and technology. China and other emerging scientific nations like South Korea, Taiwan, Brazil and Turkey are already changing the balance of power as measured by scientific production, as they are at least in part responsible for the relative decline of the former triad.     

Reasons for and developments in international scientific collaboration: does an Asia–Pacific research area exist from a bibliometric point of view?

This paper describes the different forms of and tries to give reasons for international scientific collaboration in general. It focuses on eleven countries in the Asia–Pacific region by evaluating their national research output with the help of bibliometric indicators in particular. Over two million journal articles published by these countries between 1998 and 2007 in ISI-listed periodicals are analyzed. Discipline-specific publication and citation profiles reveal national strengths and weaknesses in the different research domains. The exponential increase in publication output by China over the last few years is astonishing, but in terms of visibility, i.e. citation rates, China cannot keep up with leading science nations, remaining below the world average. A discipline-specific analysis shows that Chinese authors took an active part in more than a quarter of all articles and reviews published in the field of materials science in 2007, while their contribution to medical research is very low. Co-publication networks among the eleven countries are generated to observe the development of cooperation bonds in the region. Applying Salton’s measure of international collaboration strength, an above-average strengthening of scientific collaboration in the Asia–Pacific region can be observed.     

Research collaboration at Nordic universities

Scientific collaboration has become a major issue in science policy. The need to survey and follow up such collaboration calls for statistical indicators sensitive enough to reveal the structure and change of collaborative networks. Bibliometric analysis of co-authored scientific articles is one promising approach. This study presents data generated from a comprehensive analysis of some 20,000 articles produced by 22 Nordic universities (Denmark, Finland, Iceland, Norway, Sweden) in 1993. The results show that scientific collaboration plays a key role for all universities, and that they collaborate with external institutions in just about the same extent. The inter-Nordic university network comprises about ten percent of all institutional collaborations. However, the amount of collaboration varies across fields, physics and medicine having a high degree of collaboration. The inter-Nordic network is of equal importance as the national network in physics and geosciences. Especially, when one looks at international collaboration outside the Nordic arena, the number of overlapping partners is quite low. This suggests that research specialization is the major force governing international contacts.     

A bibliometric approach to interdisciplinarity in Japanese rice research and technology development

Research and development of rice, a major crop, has been promoted on an interdisciplinary basis with the involvement of various research fields ranging from natural sciences to socioeconomics in Japan. This paper focuses on the structure of interdisciplinarity in Japanese rice research and technology development by analyzing the relationship among all relevant disciplines with the use of a compiled bibliography of Japanese rice research with 19,389 articles in 1,611 journals in the publishing years of 1990–2000. The relationship among the disciplines was characterized by the frequency distribution of articles among journals classified into 24 categories based on the law of scattering originally identified by Bradford (Engineering 13:785–786, 1934). The 24 journal categories ranked in decreasing order of productivity of articles were divided into 3 zones; the first nuclear zone with a smaller number of highly productive journal disciplines; the second zone with a large number of less productive disciplines; and the last zone with a larger number of the least productive disciplines, which characterized the structure of interdisciplinarity in Japanese rice research and technology development. Other aspects of the interdisciplinarity were further explored with reference to peripheral journals with a minimal number of papers on a certain subject, and the Groos droop phenomenon at the end of Bradford’s S-shape curve that is the region of the least productive journals with only one paper on a certain subject, by analyzing the frequency distribution of articles in journal categories.     

The underlying characteristics of the Bradford distribution

The Bradford distribution differs from most probability distributions in that it is concerned with the rank-order S of the elements in terms of their productivity (from highest down to lowest) rather than with the numerical values n of the element's productivity. The defining relationship is that S is exponentially related to G, the cumulative production of the elements of rank-order S or less. This implies a Zipf-like relationship between mean productivity and rank-order, which is analogous to the Weber-Fechner law of Psychophysics. A variational specification of the distribution is given, and it is pointed out that the relationship between the construction of the Bradford and that of the usual distributions is roughly analogous to the relationship between Lebesgue and Riemann integration.It has been pointed out in the past that many informational data fit the approximate formula for the Bradford distribution (where n is considered to be a continuous variable). It is shown that when the exact Bradford distribution is used (with productivity taken to be an integer, as it actually is) then the fit with the data is even better, clear down to n=3,2 and even 1. This is demonstrated by fits with data from the scatter of articles on operations research among journals and also with data on the citations to a single medical journal by articles in other journals. The paper also includes tables and formulas to enable the reader to fit the distribution to data of his choice.     

Looking at science in Brazilian universities: The case of the instituto de Biofísica Carlos Chagas Filho

Performance indicators were built for the Instituto de Biofisica Carlos Chagas Filho, one of the most well-reputed Brazilian science centers. The Institute's performance presents a positive trend—articles number have doubled (1981–1995), and the articles impact grew from 4.20, in 1981, to 7.78, in 1990. This trend is probably being influenced by increasingly human resources involved in the Institute's scientific activities and by the continous growth of national and international collaboration. The follow up of indicators trends can be useful for the evaluation of long term policies directed to implement human resources programs and institutional collaborative work among scientific institutions.     

Measuring China"s research performance using the Science Citation Index

This contribution focuses on the application of bibliometric techniques to research activities in China, based on data extracted from the Science Citation Index (SCI) and related Citation Indexes, produced by the Institute for Scientific Information (ISI). The main conclusion is that bibliometric analyses based on the ISI databases in principle provide useful and valid indicators of the international position of Chinese research activities, provided that these analyses deal properly with the relatively large number of national Chinese journals covered by the ISI indexes. It is argued that it is important to distinguish between a national and an international point of view. In order to assess the Chinese research activities from a national perspective, it is appropriate to use the scientific literature databases with a good coverage of Chinese periodicals, such as the Chinese Science Citation Database (CSCD), produced at the Chinese Academy of Sciences. Assessment of the position of Chinese research from an international perspective should be based on the ISI databases, but it is suggested to exclude national Chinese journals from this analysis. In addition it is proposed to compute an indicator of international publication activity, defined as the percentage of articles in journals processed for the ISI indexes, with the national Chinese journals being removed, relative to the total number of articles published either in national Chinese or in other journals, regardless of whether these journals are processed for the ISI indexes or not. This indicator can only be calculated by properly combining CSCD and ISI indexes. This revised version was published online in June 2006 with corrections to the Cover Date.     

International research collaborations of ASEAN Nations in economics, 1979–2010

This study examines the research performance and international research collaborations (IRC) of ASEAN nations in the area of economics. Over the last 3 decades international collaborated papers have increased in the region, while locally-co-authored papers have declined. Singapore towered among ASEAN nations in research efficiency based on geographical area, population and GDP. Vietnam performed relatively better in research efficiency than research productivity (number of papers produced), while Indonesia performed poorly. Overall, internationally co-authored papers were cited twice as often as locally authored papers except that both The Philippines and Indonesia exhibited almost no difference in how their local and internationally co-authored papers were cited. The study also examined IRC from the perspective of social networks. Centrality had a strong correlation with research performance; however, vertex tie-strength (a result of repeat collaboration) showed maximum correlation with research performance. While Malaysia emerged as the nation with the highest betweenness centrality or ‘bridging’ power, the US emerged as the most favoured international partner of ASEAN nations. However, collaboration between ASEAN countries accounted for just 4 % of all international collaborations. Increased academic mobility and more joint scientific works are suggestions to consider to boost educational co-operation among the ASEAN nations.     

Scientific production on tetrachloro-dibenzo-dioxins: A bibliometric study

Summary Tetrachloro-dibenzo-dioxins were declared as human carcinogenic substances in 1997. Objective: to analyse the scientific production about tetrachloro-dibenzo-dioxins between 1976 and 2005. Solla Price and Bradford models were applied. Different aspects of papers were analysed. Impact factor of journals was studied. 3484 articles were found. The number of articles published each year is fitted to Solla Price model. It has been shown the scientific literature dispersion. Specialisation of some journals of Nucleus and 1st Bradford Zone has been shown.     

Spanish scientific and technical journals. State of the art

This article analyses the current situation in the field of scientific and technical journals published in Spain, by determining the following scientific indicators for each: I: Specifications. II: Scientific production covered. III: Visibility and accessibility. The first section provides a qualitative and quantitative study of the journals, asking what subjects they cover, who publishes them, how often they are published, how up to data they are and whether the way they are presented meets international publishing standards. The second section analyses scientific production by research sectors and the percentage of articles collected in the ICYT database compared with the total number of papers published in the journals studied. It also studies the reference habits of the authors published therein to identify whether the literature referred to is of local origin or international. Finally, the third section deduces these journals' degree of visibility by analysing how they are distributed amongst the usual media, i.e. international periodicals directories and databases, and how efficiently they work as vehicles for the diffusion of research by foreign authors. The study covers 10 years (1980–1989), thus enabling to recognise past and current trends in Spanish scientific literature.     

Technological Relevance of Science: An Assessment of Citation Linkages between Patents and Research Papers

Patent citations to the research literature offer a way for identifying and comparing contributions of scientific and technical knowledge to technological development. This case study applies this approach through a series of analyses of citations to Dutch research papers listed on Dutch-invented and foreign patents granted in the US during the years 1987–1996.First, we examined the general validity and utility of these data as input for quantitative analyses of science-technology interactions. The findings provide new empirical evidence in support of the general view that these citations reflect genuine links between science and technology. The results of the various analyses reveal several important features of industrially relevant Dutch science: (1) the international scientific impact of research papers that are also highly cited by patents, (2) the marked rise in citations to Dutch papers on foreign-invented patents; (3) the large share of author-inventor self-citations in Dutch-invented patents; (4) the growing relevance of the life sciences, (5) an increase in the importance of scientific co-operation. We also find significant differences between industrial sectors as well as major contributions of large science-based multinational enterprises, such as Philips, in domestic science-technology linkages.The paper concludes by discussing general benefits and limitations of this bibliometric approach for macro-level analysis of science bases in advanced industrialised countries like the Netherlands.     

The value of an overseas research trip

As an essential part of the academic environment, international scientific mobility draws considerable attention from researchers. Previous studies have indicated a strong relationship between scientific mobility and scientific output. However, few researchers have addressed the causality between them. The research questions in this study focused on how the international scientific mobilization of the researchers affects their number of international collaborations, their ability to get published at higher impact factor journals, the number of citations that they get. Based on the SCOPUS database of English language scientific journal articles, this paper revealed the causal effects of international scientific mobility of the researchers on their scientific productivity, collaborations, and impact on science using the synthetic control method. The author’s affiliation on their articles provided the geographical location that can be tracked in time to infer the international scientific mobility of each author. A sample of more than 79,000 immobile scientists was used to create the synthetic versions of over 1500 internationally mobile scientists, so that, the synthetic version of each mobile author best resembled the academic ability of her/his counterpart mobile author in the pre-mobilization period. This allowed investigating the effects of the international mobilization on their publications by comparing the post-mobilization publication characteristics of the mobile authors and their immobile synthetic controls.The findings show strong evidence of a substantial positive effect of scientific mobility on the ability to get published in more prestigious journals, the number of citations received in total and from overseas, and international collaborations. The magnitude of the effect is conditional on the duration of scientific mobility.

     

Comparison and evaluation of Chinese research performance in the field of bioinformatics

Bioinformatics is an emerging and rapidly evolving discipline. The bioinformatics literature is growing exponentially. This paper aims to provide an integrated bibliometric study of the knowledge base of Chinese research community, based on the bibliometric information in the field of bioinformatics from SCI-Expanded database during the period of 2000–2005. It is found that China is productive in bioinformatics as far as publication activity in international journals is concerned. For comparative purpose, the results are benchmarked against the findings from five other major nations in the field of bioinformatics: USA, UK, Germany, Japan and India. In terms of collaboration profile, the findings imply that the collaborative scope of China has gradually transcended boundaries of organizations, regions and nations as well. Finally, further analyses on the citation share and some surrogate scientometric indicators show that the publications of Chinese authors suffer from a lowest international visibility among the six countries. Strikingly, Japan has achieved most remarkable impact of publication when compared to research effort devoted to bioinformatics amongst the six countries. The policy implication of the findings lies in that Chinese scientific community needs much work on improving the research impact and pays more attention to strengthening the academic linkages between China and worldwide nations, particularly scientifically advanced countries.     

Benchmarking international scientific excellence: Are highly cited research papers an appropriate frame of reference?

This paper introduces a citation-based "systems approach" for analyzing the various institutional and cognitive dimensions of scientific excellence within national research systems. The methodology, covering several aggregate levels, focuses on the most highly cited research papers in the international journal literature. The distribution of these papers across institutions and disciplines enables objective comparisons their (possible) international-level scientific excellence. By way of example, we present key results from a recent series of analyses of the research system in the Netherlands in the mid 1990s, focussing on the performance of the universities across the various major scientific disciplines within the context of the entire system"s scientific performance. Special attention is paid to the contribution in the world"s top 1% and top 10% most highly cited research papers. The findings indicate that these high performance papers provide a useful analytical framework - both in terms of transparency, cognitive and institutional differentiation, as well as its scope for domestic and international comparisons - providing new indicators for identifying "world class" scientific excellence at the aggregate level. The average citation scores of these academic "Centres of Scientific Excellence" appear to be an inadequate predictor of their production of highly cited papers. However, further critical reflection and in-depth validation studies are needed to establish the true potential of this approach for science policy analyses and evaluation of research performance. This revised version was published online in August 2006 with corrections to the Cover Date.     

Comparisons of content and scientific quality indicators across peer-reviewed journal articles with more or less gender perspective: gender studies can do better

The field of gender studies has faced criticism for poor scholarship and methodology, both from within and outside academia. Here, we compare indicators of scientific quality across three samples of peer-reviewed journal articles with more, less and no gender perspective, on the assumption that gender studies tend to apply a gender perspective. The statements in the articles were content-analysed with respect to subject matter, their level of support in surrounding text, and other indicators of scientific quality. The higher the level of gender perspective, the lower was the scientific quality for seven out of nine indicators. Support was higher for the no gender perspective group, but did not differ across the two higher levels. We suggest that the impact of the field can be increased by implementing established research methods employed in other disciplines, especially in terms of bringing about desired social and societal change.     

International comparisons of scientific performance revisited

This paper presents a methodological analysis of the latest update of the CHI/NSF Science Literature Indicators Data-Base. The data-base contains a range of publication and citation indicators borken down by country and field or subfield, and now convers the period from 1973 to 1984. It can be used to draw comparisons of the changing output and impact of basic research in different countries. Earlier applications of the data-base have been constrained by various technical limitations, and have been subject to certain criticism. In this article, after some conceptual analysis of what aspects of scientific performance the different indicators relate to, we show that much of the criticism is misplaced. We also describe subsequent methodological improvements to the indicators and the effect these have on the policy use that can be made. Finally, we examine what the latest statistics reveal about the relative international standing of seven leading scientific nations.     

The Holy Grail of science policy: Exploring and combining bibliometric tools in search of scientific excellence

Evaluation studies of scientific performance conducted during the past years more and more focus on the identification of research of the 'highest quality', 'top' research, or 'scientific excellence'. This shift in focus has lead to the development of new bibliometric methodologies and indicators. Technically, it meant a shift from bibliometric impact scores based on average values such as the average impact of all papers published by some unit to be evaluated towards indicators reflecting the topof the citation distribution, such as the number of 'highly cited' or 'top' articles. In this study we present a comparative analysis of a number of standard and new indicators of research performance or 'scientific excellence', using techniques applied in studies conducted by CWTS in recent years. It will be shown that each type of indicator reflects a particular dimension of the general concept of research performance. Consequently, the application of one single indicator only may provide an incomplete picture of a unit's performance. It is argued that one needs to combine the various types of indicators in order to offer policy makers and evaluators valid and useful assessment tools. This revised version was published online in August 2006 with corrections to the Cover Date.