Diversity of references as an indicator of the interdisciplinarity of journals: Taking similarity between subject fields into account

TLDR

The study is limited to seven journals covering 15,757 articles, indicating that further research is needed to generalize the findings. The article aims to advance the study of journal interdisciplinarity by examining knowledge integration at the article level. Interdisciplinarity is quantified by the diversity of subject fields in an article’s reference list, using the Euven‑Budapest classification and a Hill‑type true diversity that incorporates variety, balance, and disparity, applied in three analytical steps. The Hill‑type diversity measure proves to be a viable interdisciplinarity indicator, works across journals from mathematics to social sciences, and shows that interdisciplinary research does not automatically lead to higher visibility or impact.

Abstract

The objective of this article is to further the study of journal interdisciplinarity, or, more generally, knowledge integration at the level of individual articles. Interdisciplinarity is operationalized by the diversity of subject fields assigned to cited items in the article's reference list. Subject fields and subfields were obtained from the L euven‐ B udapest ( ECOOM ) subject‐classification scheme, while disciplinary diversity was measured taking variety, balance, and disparity into account. As diversity measure we use a H ill‐type true diversity in the sense of J ost and L einster‐ C obbold. The analysis is conducted in 3 steps. In the first part, the properties of this measure are discussed, and, on the basis of these properties it is shown that the measure has the potential to serve as an indicator of interdisciplinarity. In the second part the applicability of this indicator is shown using selected journals from several research fields ranging from mathematics to social sciences. Finally, the often‐heard argument, namely, that interdisciplinary research exhibits larger visibility and impact, is studied on the basis of these selected journals. Yet, as only 7 journals, representing a total of 15,757 articles, are studied, albeit chosen to cover a large range of interdisciplinarity, further research is still needed.