Bibliometric Indicators of Interdisciplinarity Exploring New Class of Diversity Measures

In bibliometrics, interdsicsiplinatity is often measured in terms of the "diversity" of research areas in the references that an article cites. The standard indicators used are borrowed mostly from other research areas, notably from ecology (biodiversity measures) and economics (concentration measures). This paper discusses a new class of measures, which are used in the study of biodiversity and especially the Leinster-Cobbold diversity measure (Leinster Cobbold 2010). We present a case study based on previously published dataset of 12 journal articles from a group of five researchers from the bio-nano science described and published by Rafols and Meyer (2010). We replicate the findings of this study to show that the various interdisciplinarity measures are in fact special cases of the Cobbold-Leinster diversity measure. The paper discusses some interesting properties of the Cobbold-Leinster diversity measure, which makes it appealing in the study of disciplinary diversity than the standards diversity indicators used as proxy for interdisciplinarity. Conference Topic Indicators Introduction Considerable efforts have been made to operationalize and measure the concept of interdisciplinarity in bibliometrics (Porter et al., 2007; Rafols & Meyer, 2010). The most commonly used indicators of interdisciplinarity are mostly borrowed from other research areas, notably from ecology (biodiversity measures) and economics (concentration measures). The purpose of this paper is to bring to discussion a relatively new class of diversity indicators which are used in ecology but so far not been used to investigate disciplinary diversity. Drawing from the literature in ecology, the paper highlights important properties of those measures and discusses how they can help the bibliometric study of interdisciplinarity. The paper is divided in three parts. The next section briefly presents indicators of interdisciplinarity in bibliometrics. The second section discusses the development of new class of diversity measures used in ecology and presents the Leinster-Cobbold diversity measure, highlighting its properties and why they are relevant for bibliometric usage. The third section presents a case study to illustrate the potential of Leinster-Cobbold diversity indicators as a measure of disciplinary diversity. Currently used Bibliometric indicators of interdisciplinarity Bibliometric analyses of interdisciplinarity take as unit of analysis a scientific paper and assume that the extent to which it integrates elements of different disciplines is reflected in the references it cites. References in scientific papers are expected to reflect various aspects of interdisciplinary because researchers will credit what they are indebted to other disciplines: conceptually (concepts, ideas and approaches from other disciplines); analytically (methods for defining, collecting and analyze data) and technically (tools developed in other fields). 1 The views expressed in this paper are the authors’. They do not necessarily reflect the views or official positions of the European Commission, the European Research Council Executive Agency or the ERC Scientific Council.