7.1.2Two basic concepts in interdisciplinarity studies

In 2010, Rafols and Meyer proposed to use two main concepts to characterise interdisciplinarity in terms of knowledge integration. These central concepts are diversity and coherence.

The first one is diversity. Stirling (1994), has proposed three specific components of diversity, in particular, varietybalance, and disparity. The first two components reflect number and distribution of disciplines referred to in the document under study, while disparity also considers how different these referenced disciplines are in terms of their cognitive distance (cf. Zhang et al., 2016).

The second concept is coherence. While diversity measures characteristics of cognitive heterogeneity, coherence relates to a process in which different topics, methods or data become related. Rafols and Meyer (2010) proposed the use of both concepts for studying knowledge integration. Unlike the diversity, coherence does not explicitly require any predefined subject classification system.

The combination of the two concepts provides further specification of interdisciplinarity and may be useful in studying emerging fields, where new and controversial categorizations are accompanied by equally contested claims of novelty and interdisciplinarity (Rafols and Meyer, 2010). The three-aspect model (density, intensity and disparity) can be extended to the concept of coherence as well (Rafols, 2014).