The importance of collaborative networks in Canadian scientific research

Abstract

This study investigates co-author and co-inventor collaborations using scientific articles and patents to measure collaborative knowledge production. This paper assesses how a scientist’s position within the joint co-publication and co-invention network affects its production and citation impact. Our findings reveal that number of publications is strongly associated with the scientists’ position in co-author/inventor networks and that a scientist’s technological production actually increases with collaboration in such networks. These academic relationships have a significant impact on the future number of publication citations and appear to benefit the number of patent citations in the same measure.     

On fundamental regularities of the distribution of scientific productivity

This paper presents a methodologicl and mathematical study of the main regularities related to the distribution of scientific productivity. An analysis of the se regularities is given from the point of view of two approaches, the frequency and the rank approaches, to the problem of scientific productivity. The connection between these approaches is studied and a number of mathematical formulas that are both of theoretical significance for the understanding of information data basis formation mechanisms and of practical one, in particular, for the estimate of Bradford's law parameters, are deduced. The relation between the scientific productivity distributions under consideration and the stable non-Gaussian distributions is analyzed. The formation of the corresponding regularities of scientific productivity is regarded as a consequence of probability process combined with deterministic one.     

The law of limited excellence: publication productivity of Israel Prize laureates in the life and exact sciences

The present paper extends Lotka’s theorem—which we rename as “the law of limited excellence”—while empirically modelling the scientific productivity of 46 Israel Prize laureates in the life and exact sciences—a group best described as ‘Star Scientists’. By focusing on this highly selective group we expose unequal scientific productivity even amongst Israel’s most prolific scientists. Specifically, we test the invariance of Lotka’s law by focusing attention on the extreme tail of publication distributions while empirically exploring the non-linearity of its seemingly “flat” tail. By exposing the rarity of excellence even in this extreme end of publication productivity we extend the generality of Lotka’s theorem and expose that—like a fractal—the tail of excellence behaves as the entire distribution. We end this empirical contribution by suggesting a few implications for research and policy.     

Quantifying scientific collaboration impact by exploiting collaboration-citation network

Despite the growing interest in exploring the collaboration patterns and the structure of collaboration networks, the impact of collaboration associated with time-varying scholarly networks is hardly known. This paper investigates collaboration and productivity in a science career and quantifies the impact of collaboration in the collaboration-citation network. Moreover, this paper also investigates collaboration patterns and examines the typical duration of research collaborations. A SCIRank model is proposed to quantify the impact of scientific collaboration, which not only reveals the impact of co-author pairs but also identifies scholarly papers with the outstanding impact that leads to Nobel Prize awards.

     

The structure and analysis of nanotechnology co-author and citation networks

Research activities and collaborations in nanoscale science and engineering have major implications for advancing technological frontiers in many fields including medicine, electronics, energy, and communication. The National Nanotechnology Initiative (NNI) promotes efforts to cultivate effective research and collaborations among nano scientists and engineers to accelerate the advancement of nanotechnology and its commercialization. As of August 2008, there have been over 800 products considered to benefit from nanotechnology directly or indirectly. However, today’s accomplishments in nanotechnology cannot be transformed into commercial products without productive collaborations among experts from disparate research areas such as chemistry, physics, math, biology, engineering, manufacturing, environmental sciences, and social sciences. To study the patterns of collaboration, we build and analyze the collaboration network of scientists and engineers who conduct research in nanotechnology. We study the structure of information flow through citation network of papers authored by nano area scientists. We believe that the study of nano area co-author and paper citation networks improve our understanding of patterns and trends of the current research efforts in this field. We construct these networks based on the publication data collected for years ranging 1993 through 2008 from the scientific literature database “Web of Science”. We explore those networks to find out whether they follow power-law degree distributions and/or if they have a signature of hierarchy. We investigate the small-world characteristics and the existence of possible community structures in those networks. We estimate the statistical properties of the networks and interpret their significance with respect to the nano field.     

Evaluating scholars based on their academic collaboration activities: two indices, the RC-index and the CC-index, for quantifying collaboration activities of researchers and scientific communities

Although there are many studies for quantifying the academic performance of researchers, such as measuring the scientific performance based on the number of publications, there are no studies about quantifying the collaboration activities of researchers. This study addresses this shortcoming. Based on three measures, namely the collaboration network structure of researchers, the number of collaborations with other researchers, and the productivity index of co-authors, two new indices, the RC-Index and CC-Index, are proposed for quantifying the collaboration activities of researchers and scientific communities. After applying these indices on a data set generated from publication lists of five schools of information systems, this study concludes with a discussion of the shortcomings and advantages of these indices.     

Measuring the stability of scientific collaboration

Stability has long been regarded as an important characteristic of many natural and social processes. In regards to scientific collaborations, we define stability to reflect the consistent investment of a certain amount of effort into a relationship. In this paper, we provide an explicit definition of a new indicator of stability, based on the year-to-year publication output of collaborations. We conduct a large-scale analysis of stability among collaborations between authors publishing in the field of computer science. Collaborations with medium–high degree of stability tend to occur most frequently, and on average, have the highest average scientific impact. We explore other “circumstances”, reflecting the composition of collaborators, that may interact with the relationship between stability and impact, and show that (1) Transdisciplinary collaborations with low stability leads to high impact publications; (2) Stable collaboration with the collaborative author pairs showing greater difference in scientific age or career impact can produce high impact publications; and (3) Highly-cited collaborators whose publications have a large number of co-authors do not keep stable collaborations. We also demonstrate how our indicator for stability can be used alongside other similar indicators, such as persistence, to better understand the nature of scientific collaboration, and outline a new taxonomy of collaborations.     

The evaluation of university departments and their scientists: Some general considerations with reference to exemplary bibliometric publication and citation analyses for a Department of psychology

In reference to an exemplary bibliometric publication and citation analysis for a University Department of Psychology, some general conceptual and methodological considerations on the evaluation of university departments and their scientists are presented. Data refer to publication and citation-by-others analyses (PsycINFO, PSYNDEX, SSCI, and SCI) for 36 professorial and non-professorial scientists from the tenure staff of the department under study, as well as confidential interviews on self-and colleagues-perceptions with seven of the sample under study. The results point at (1) skewed (Pareto-) distributions of all bibliometric variables demanding nonparametrical statistical analyses, (2) three personally identical outliers which must be excluded from some statistical analyses, (3) rather low rank-order correlations of publication and citation frequencies having approximately 15% common variance, (4) only weak interdependences of bibliometric variables with age, occupational experience, gender, academic status, and engagement in basic versus applied research, (5) the empirical appropriateness and utility of a normative typological model for the evaluation of scientists’ research productivity and impact, which is based on cross-classifications with reference to the number of publications and the frequency of citations by other authors, and (6) low interrater reliabilities and validity of ad hoc evaluations within the departments’ staff. Conclusions refer to the utility of bibliometric data for external peer reviewing and for feedback within scientific departments, in order to make colleague-perceptions more reliable and valid.     

Crossing the hurdle: the determinants of individual scientific performance

An original cross-sectional dataset referring to a medium-sized Italian university is implemented in order to analyze the determinants of scientific research production at individual level. The dataset includes 942 permanent researchers of various scientific sectors for a 3-year time-span (2008–2010). Three different indicators—based on the number of publications and/or citations—are considered as response variables. The corresponding distributions are highly skewed and display an excess of zero-valued observations. In this setting, the goodness-of-fit of several Poisson mixture regression models are explored by assuming an extensive set of explanatory variables. As to the personal observable characteristics of the researchers, the results emphasize the age effect and the gender productivity gap—as previously documented by existing studies. Analogously, the analysis confirms that productivity is strongly affected by the publication and citation practices adopted in different scientific disciplines. The empirical evidence on the connection between teaching and research activities suggests that no univocal substitution or complementarity thesis can be claimed: a major teaching load does not affect the odds to be a non-active researcher and does not significantly reduce the number of publications for active researchers. In addition, new evidence emerges on the effect of researchers administrative tasks—which seem to be negatively related with researcher’s productivity—and on the composition of departments. Researchers’ productivity is apparently enhanced by operating in department filled with more administrative and technical staff, and it is not significantly affected by the composition of the department in terms of senior/junior researchers.     

A scientometrics law about co-authors and their ranking: the co-author core

Rather than “measuring” a scientist impact through the number of citations which his/her published work can have generated, isn’t it more appropriate to consider his/her value through his/her scientific network performance illustrated by his/her co-author role, thus focussing on his/her joint publications, and their impact through citations? Whence, on one hand, this paper very briefly examines bibliometric laws, like the h-index and subsequent debate about co-authorship effects, but on the other hand, proposes a measure of collaborative work through a new index. Based on data about the publication output of a specific research group, a new bibliometric law is found. Let a co-author C have written J (joint) publications with one or several colleagues. Rank all the co-authors of that individual according to their number of joint publications, giving a rank r to each co-author, starting with r = 1 for the most prolific. It is empirically found that a very simple relationship holds between the number of joint publications J by coauthors and their rank of importance, i.e., J ∝ 1/r. Thereafter, in the same spirit as for the Hirsch core, one can define a “co-author core”, and introduce indices operating on an author. It is emphasized that the new index has a quite different (philosophical) perspective that the h-index. In the present case, one focusses on “relevant” persons rather than on “relevant” publications. Although the numerical discussion is based on one “main author” case, and two “control” cases, there is little doubt that the law can be verified in many other situations. Therefore, variants and generalizations could be later produced in order to quantify co-author roles, in a temporary or long lasting stable team(s), and lead to criteria about funding, career measurements or even induce career strategies.     

Productivity, impact and publication habits by gender in the area of Materials Science

Summary A comparative analysis of the scientific performance of male and female scientists in the area of Materials Science at the Spanish Council for Scientific Research (CSIC) is presented. Publications of 333 scientists during 1996-2000 are downloaded from the international database Science Citation Index and the national one ICYT. Scientific performance of scientists is studied through different indicators of productivity (number of SCI and ICYT publications), international visibility (average impact factor of publications, percentage of documents in “top journals”) and publication practices (%international publications, signing order of authors in the documents and different collaboration measures). Inter-gender differences in the research performance of scientists are studied. Influence of professional category and age are analysed. Although women are less productive than men, no significant differences in productivity are found within each professional category. However, a different life-cycle of productivity is found for men and woman and the most important inter-gender differences in productivity occur at the ages of 40-59.     

A new indicator for international visibility: exploring Brazilian scientific community

Brazilian science has increased fast during the last decades. An example is the increasing in the country’s share in the world’s scientific publication within the main international databases. But what is the actual weight of international publications to the whole Brazilian productivity? In order to respond this question, we have elaborated a new indicator, the International Publication Ratio (IPR). The data source was Lattes Database, a database organized by one of the main Brazilian S&;T funding agency, which encompasses publication data from 1997 to 2004 of about 51,000 Brazilian researchers. Influences of distinct parameters, such as sectors, fields, career age and gender, are analyzed. We hope the data presented may help S&;T managers and other S&;T interests to better understand the complexity under the concept scientific productivity, especially in peripheral countries in science, such as Brazil.     

Are academics who publish more also more cited? Individual determinants of publication and citation records

Thanks to a unique individual dataset of French academics in economics, we explain individual publication and citation records by gender and age, co-authorship patterns (average number of authors per article and size of the co-author network) and specialisation choices (percentage of output in each JEL code). The analysis is performed on both EconLit publication scores (adjusted for journal quality) and Google Scholar citation indexes, which allows us to present a broad picture of knowledge diffusion in economics. Citations are largely driven by publication records, which means that these two measures are partly substitutes, but citations are also substantially increased by larger research team size and co-author networks.     

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.

     

Lotka's law reconsidered: The evolution of publication and citation distributions in scientific fields

This paper reports early steps in research that seeks to clarify how publications of scientists interact dynamically with citations and reputation in shaping the evolution of scientific fields. We assume that Lotka's modified law holds for scientific fields. A primary approach to model publication productivity was published by Yablonsky. In contrast to Yablonsky's unfinished mathematical approach, our simulation approach is not predominantly driven by insight into the formal generation mechanisms of certain processes but more theory driven. It considers the evolution of publication and citation distributions over the histories of scientific fields using both simulated and real historical data.     

Discovering cross-topic collaborations among researchers by exploiting weighted association rules

Identifying the most relevant scientific publications on a given topic is a well-known research problem. The Author-Topic Model (ATM) is a generative model that represents the relationships between research topics and publication authors. It allows us to identify the most influential authors on a particular topic. However, since most research works are co-authored by many researchers the information provided by ATM can be complemented by the study of the most fruitful collaborations among multiple authors. This paper addresses the discovery of research collaborations among multiple authors on single or multiple topics. Specifically, it exploits an exploratory data mining technique, i.e., weighted association rule mining, to analyze publication data and to discover correlations between ATM topics and combinations of authors. The mined rules characterize groups of researchers with fairly high scientific productivity by indicating (1) the research topics covered by their most cited publications and the relevance of their scientific production separately for each topic, (2) the nature of the collaboration (topic-specific or cross-topic), (3) the name of the external authors who have (occasionally) collaborated with the group either on a specific topic or on multiple topics, and (4) the underlying correlations between the addressed topics. The applicability of the proposed approach was validated on real data acquired from the Online Mendelian Inheritance in Man catalog of genetic disorders and from the PubMed digital library. The results confirm the effectiveness of the proposed strategy.

     

Were has the cumulative advantage gone? Some observations about the frequency distribution of scientific productivity,of duration of scientific participation,and of speed of publication

Frequency distributions of scientific productivity are usually based on cross section cuts of the investigated population of scientists. Therefore, some of the registered scientists are involved for the whole period of time, but there are many fractional authors, too. If one compares only scientists active in a specialty for the same length of time, the typical bibliometric skewness of the distribution vanishes. But also the duration of participation of a cohort of scientists which began their career in the same year is not distributed in a Lotkean manner. Furthermore, the speed of publication-which might be a better statistical indicator of scientific capacities than publication output as such—has more similarity to a normal distribution than to a lognormal one.     

Gender gaps in international research collaboration: a bibliometric approach

This paper addresses gender differences in international research collaboration measured through international co-authorship. The study is based on a dataset consisting of 5600 Norwegian researchers and their publication output during a 3-year period (44,000 publications). Two different indicators are calculated. First, the share of researchers that have been involved in international collaboration as measured by co-authorship, and second, the share of their publications with international co-authorship. The study shows that the field of research is by far the most important factor influencing the propensity to collaborate internationally. There are large differences from humanities on the one hand, where international collaboration in terms of co-authorship is less common, to the natural sciences on the other, where such collaboration is very frequent. On an overall level, we find distinct gender differences in international research collaboration in Norway in the favour of men. However, men and women are not equally distributed across fields and there are relatively more female researchers in fields where the international collaboration rates generally are lower. When the data are analysed by scientific field, academic position, and publication productivity of the researchers, the gender differences in the propensity to collaborate with colleagues in other countries are minor only, and not statistically significant. Concerning gender inequality in science, the main challenge seems to be the lower productivity level of female researchers, which obviously hinders their academic career development. Differences in international collaboration are unlikely to be an important factor in this respect, at least not in the Norwegian research context analysed in this study.