Ed C. M. Noyons

A unified approach to mapping and clustering of bibliometric networks

In the analysis of bibliometric networks, researchers often use mapping and clustering techniques in a combined fashion. Typically, however, mapping and clustering techniques that are used together rely on very different ideas and assumptions. We propose a unified approach to mapping and clustering of bibliometric networks. We show that the VOS mapping technique and a weighted and parameterized variant of modularity-based clustering can both be derived from the same underlying principle. We illustrate our proposed approach by producing a combined mapping and clustering of the most frequently cited publications that appeared in the field of information science in the period 1999-2008.

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.

Combining mapping and citation analysis for evaluative bibliometric purposes: a bibliometric study

The general aim of the article is to demonstrate how the results both of a structural analysis, and of a research performance assessment of a research field, can be enriched by combining elements of both into one integrated analysis. In addition, a procedure is discussed to select and analyse candidate benchmark institutes to assess the position of a particular research institute, in terms of both its cognitive orientation and its scientific production and impact at the international research front. The combined method is applied in an evaluation of the research scope and performance of the Inter‐university Centre for Micro‐Electronics (IMEC) in Leuven, Belgium. On the basis of the comments of an international panel of experts in micro‐electronics, the method was discussed in detail. We concluded that the method provides a detailed and useful picture of the position of the institute from an international perspective. Moreover, we found that the results of each of the two parts are an added value to the other.

Monitoring scientific developments from a dynamic perspective: self-organized structuring to map neural network research

With the help of bibliometric mapping techniques, we have developed a methodology of “self-organized” structuring of scientific fields. This methodology is applied to the field of neural network research. We propose a field-definition based on the present situation. This is done by letting the data themselves generate a structure, and, with that, define the subdivision of the research field into meaningful subfields. In order to study the evolution over time, the above “self-organized” definition of the present structure is taken as a framework for the past structure. We explore this evolution by monitoring the interrelations between subfields and by zooming into the internal structure of each subfield. The overall (“coarse”) structure and the detailed subfield maps (“fine structure”) are used for monitoring the dynamical features of the entire research field. Furthermore, by determining the positions of the main actors on the map, these structures can also be used to assess the activities of these main actors (universities, firms, countries, etc.). Finally, we “reverse” our approach by analyzing the developments based on a structure generated in the past. Comparison of the “real present” and the “present constructed from the past” may provide new insight into successful, as well as unsuccessful, patterns and “trajectories” of developments. Thus, we explore the potential of our method to put the observed “actual” developments into a possible future perspective.

Bibliometric mapping of science in a policy context

Despite the promising introduction of bibliometric maps of science in a science policy context in the nineteen seventies, they have not been very successful yet. It seems, however, that only now they are becoming acknowledged as a useful tool. This is mainly due to the developments and integration of hypertext and graphical interfaces. Because of this, the strength of such navigation tools becomes obvious. The communication through the Internet enables the field expert (as a kind of peer review) as well as the user (from a science policy context) to contribute to the quality of the map and the interface. Moreover, the interface can provide suggestions to answer policy-related question, which is the initial purpose of such maps.

Exploring the science and technology interface: inventor-author relations in laser medicine research

Abstract The aim of this study is to investigate a specific aspect of the science and technology interface: inventor-author relations. The subject area is application of lasers in medicine. The empirical material consists of a set of 30 patents, representing the ‘technology side’ and 1057 publications authored by the inventors, representing the ‘science side’ of lasers in medicine. Our study includes four different approaches. First, we tried to find evidence, by looking at the scientific part, for the claim that references in patents to non-patent literature (NPL references, mostly scientific publications) indicate ‘science intensity’. It appeared that inventors of patents with many NPL references did not publish significantly more in science than inventors of patents with few NPL references. The former did, however, use more basic scientific journals to publish in than the latter. Second, we tried to identify at the science side one paper per patent which would best represent the RD and (2) companies and universities level up their co-operation.

Automatic term identification for bibliometric mapping

A term map is a map that visualizes the structure of a scientific field by showing the relations between important terms in the field. The terms shown in a term map are usually selected manually with the help of domain experts. Manual term selection has the disadvantages of being subjective and labor-intensive. To overcome these disadvantages, we propose a methodology for automatic term identification and we use this methodology to select the terms to be included in a term map. To evaluate the proposed methodology, we use it to construct a term map of the field of operations research. The quality of the map is assessed by a number of operations research experts. It turns out that in general the proposed methodology performs quite well.

How to identify research groups using publication analysis: an example in the field of nanotechnology

SummaryWe present a new bibliometric approach to identify research groups in a particular research field. With a combination of bibliometric mapping techniques and network analysis we identify and classify clusters of authors to represent research groups. In this paper we illustrate the application and potential of this approach and present two types of outcomes: actual research groups and potential research groups. The former enables us to define research groups beyond the organizational structure. The latter may be used to identify potential partners for collaboration. Our approach is a starting point to deal with the complex issue of research groups in a changing structure of scientific research.

International Comparison of Departments' Research Performance in the Humanities.

Methods are developed to compare the research performance of departments in two humanities disciplines, general linguistics and general literature. Departments from an Anglo‐Saxon country were compared with several departments from European, non‐Anglo‐Saxon countries. A method was developed to reconstruct publication lists of departments, based on searches in various databases. We were able to retrieve 98% of the citations given to the work of one particular department. In both disciplines, it was found that the impact of some departments was largely dependent on their books and chapters, while other departments received most citations from their journal articles. The origins of citations were traced. Some departments had a largely local impact, whereas others showed a more cosmopolitan impact. Although there was some evidence of continental “self‐citations,” citations were also given across continents. The results indicate that bibliometric assessment of research performance is potentially useful in these humanities disciplines.

Combining mapping and citation network analysis for a better understanding of the scientific development: The case of the absorptive capacity field

The general aim of this paper is to show the results of a study in which we combined bibliometric mapping and citation network analysis to investigate the process of creation and transfer of knowledge through scientific publications. The novelty of this approach is the combination of both methods. In this case we analyzed the citations to a very influential paper published in 1990 that contains, for the first time, the term Absorptive Capacity. A bibliometric map identified the terms and the theories associated with the term while two techniques from the citation network analysis recognized the main papers during 15 years. As a result we identified the articles that influenced the research for some time and linked them into a research tradition that can be considered the backbone of the “Absorptive Capacity Field”.