7.5.1Disciplines and their differences


The concept of disciplines

To understand inter-disciplinarity, one must first consider the concept of disciplines. What is a scientific discipline? In a broad overview of the literature, Sugimoto and Weingart (2015) find that disciplines have been characterized as more or less coherent “units of intellectual content”, with clear social, communicative, and institutional features. That is, a body of research on a specific problem, approached using certain methods, can only be recognized as a discipline if it is studied by a community of researchers, with their own discourse and some form of institutionalization (journals, conferences, education…). In addition, a discipline needs to be recognizable as a separate entity from other, related disciplines.

Since disciplines are multi-faceted entities, it’s no surprise that they have been studied and operationalized in different ways. Daraio and Glänzel (2016) mention four types of disciplinary classifications:

  • Administrative: as seen by government or policy makers;
  • Cognitive or epistemic: based on contents, either on the disciplinary profile of the publication channel (e.g., journal) or on the contents of the individual publication;
  • Organizational: based on organizational structure;
  • Qualification-based: based on education and competencies.

Through a comparison of a cognitive and organizational classification, Guns et al. (2018) find that “all organizational disciplines are to some extent prone to publishing ‘outside’ one’s own discipline but there are great differences between disciplines”. Cognitive classifications at the journal level have been shown to carry traces from the context in which they originate (Sīle et al., 2021). Such classifications have two main disadvantages: (1) research in multidisciplinary journals cannot adequately be represented and (2) even disciplinary journals may publish publications that contribute to other disciplines. On the other hand, while cognitive classifications at the publication level may solve these issues, they can be labour-intensive or require computationally demanding procedures to cluster publications based on, e.g., citations (Waltman & Eck, 2012) or textual data (Eykens et al., 2020).

Diversity of disciplines

In one of the first major bibliometric texts published, Derek de Solla Price (1963) pointed towards the differences in publication and citation/referencing practices between different disciplines. Since then, numerous other studies have appeared which all make important nuances about particular cases, but basically argue along similar lines: each field or discipline has its own knowledge objects or subjects, conceptual frameworks, sets of relevant research questions and preferred methodologies. Due to this epistemological identity, among other factors, every discipline follows a particular way of communicating research. These differences range from the ways in which research from predecessors is acknowledged to publication formats and writing styles – the so-called practice of communicating research.

Although there are other important factors at play, the epistemological identity of a discipline to a large extent influences its communication practices. This heterogeneity is important because it complicates the design of discipline-invariant indicators for interdisciplinarity. Let us first look at a broad division, the split between the science, technology, engineering, and medical sciences (STEM disciplines) on the one hand, and the SSH on the other.

Differences between STEM and SSH. The fluidity and dynamicity of knowledge subjects in SSH disciplines makes these disciplines stand out in terms of their communication practices. A first important difference is that an endless number of variables can be taken into account in explanations for social phenomena. These social phenomena themselves are also constantly changing. Hence, problem-solving is more complex. In fact, some SSH research takes the form of contributing additional perspectives to phenomena of interest, rather than attempting to answer a question or solve a particular problem. The complexity of some puzzles in the SSH sometimes demands a lengthy argument, and when many factors are taken into account, a plea needs to build on an extensive list of previous references supporting researchers’ decisions.

It follows that the form of the publications in the SSH in general differs from those in STEM disciplines. SSH publications are, for example, more lengthy on average. Scholars from SSH disciplines communicate their findings in books or monographs more often (Engels et al., 2012; Nederhof, 2006). Reference lists are often more lengthy and the average cited reference in a document tends to be much older than those in STEM disciplines (Glänzel & Schoepflin, 1999). In addition, depending on the research questions at hand, references may include a broad array of document types (such as grey literature, literary and historic texts, or archival materials), and publications are often written in languages other than English, generally considered the lingua franca of the sciences.

Disciplines in the SSH are multi-paradigmatic. Different theoretical or methodological schools might be trying to address different issues. This leads to the fact that many disciplines in the SSH are also multi-methodological. In contrast, STEM disciplines tackle more aligned research problems with a more or less clear set of rules and tools to study these research problems. The turn-over in ‘solved problems’ for STEM disciplines is quick and the time-horizon for noteworthy scientific revolutions which fundamentally change the ways of doing research lies far ahead. Consequently, publications are mostly written in the format of an English language journal article, citing a bolstered set of recent publications. Knowledge building is often quoted as being cumulative in these disciplines.

Diversity within the SSH. It is generally accepted that the social sciences are closer in epistemics and research and communication practice to STEM than the humanities. This overlooks, however, that there are many differences between disciplines both in social sciences and in humanities. In addition, even within disciplines, one may encounter quite some heterogeneity.

Disciplines within the SSH have been shown to differ from each other as well. Studies demonstrate that psychology and economics, for example, show many similarities with STEM disciplines, whereas others, like social work and educational sciences or law and criminology are very different. Within the humanities, similar distinctions between disciplines can be noted. Computational linguistics and the digital humanities, for instance, share cognitive and methodological aspects with computer sciences, whereas history, arts and ethics exhibit a more standard ‘humanities’ practice. Some disciplines are more locally oriented, publishing more research in Dutch or French, often through publication channels that are largely invisible in international databases and indexes. Some disciplines are more oriented towards policy or practice instead of being methodological or empirical-theoretical in nature.

The further we zoom in on these fractal divisions, we again face differences between sub-disciplines, or groups of scholars specialized in a certain topic. As noted by Becher and Trowler (2001), if we zoom in on particular departments of different universities which represent the same discipline, we may encounter very different practices. For instance, while one department might be specialized in sociological theorizing, another might be more policy-oriented. The former department might exhibit more impact in terms of publications covered in Web of Science, while the latter shows greater societal impact as measured by references in policy documents and contributions to the public debate.

In addition, disciplines are in constant flux. They grow and shrink, they differentiate into new specialties, or dissolve completely. The differentiation into new specialties can lead to the emergence of new disciplines with their own research and communication practices. These dynamic aspects of disciplines pose additional challenges for the measurement of interdisciplinarity.