Research paradigm

3.2.1 Background to research philosophies

Everyone has some form of personal perspective or philosophical belief about the nature of the world and the ways in which it is possible to understand it, even if it is rarely aired. Recognising a research paradigm within which the work has been undertaken is relevant to the thesis because it helps to make clear the systems of belief that form the researcher’s ‘point of departure’.

The various paradigms that underpin different philosophical positions are sometimes seen as discrete schools of thought: one is a positivist, an interpretivist, a rationalist. These positions are more like points on a spectrum than islands; few people now would locate themselves unambiguously below one of these banners (Bhaskar, 2008: 16). On a spectrum of positivist certainty to interpretivist uncertainty (Winter, 1989: 28-30), the profession of structural engineering may in many circumstances be placed towards the positivist end – it is, for instance, possible for an engineer to be fairly sure of the behaviour of materials and technology with which they design. Positivism assumes that an objective reality exists independent of social actors, and that through observation of measurable phenomena, causation can be determined and law-like generalisations established (Saunders et al., 2009: 119). To be able to make reliable measurements, positivist research seeks to create closed systems, like a laboratory experiment. However, this can only be achieved in relation to isolated aspects of the real-world context of the construction industry, which acts as an open, sociotechnical system.

Study of the use and experience of architecture may be considered much closer to the interpretivist end of the spectrum. Buildings can have meanings to people, but these are constructed by individuals in a tapestry of their past experiences, perspectives, and feelings at a particular moment in time. These interpretations are not fixed, universal or certain: they emerge from human bodies and minds that do not behave in reliable and predictable ways. The profession of architecture must engage with these human factors if it is to achieve more than simply functional buildings. However, unlike pure social sciences, the practice of architecture and its outcomes is not constituted solely in the minds and lives of people, like education, but is manifested in physical artefacts: the technical realisation of the built environment. Research into the use of materials in the construction industry, likewise, must address the emergence of complex behaviour involving people and organisations, but has at its core the external reality of materials, rather than constructed human relations and interpretations. In this context, critical realism is a valuable alternative paradigm in the realm between positivism and interpretivism.

3.2.2 Critical realism

Originating from Roy Bhaskar and Rom Harré in the 1970s (Danermark et al., 2005), critical realism acknowledges the subjective knowledge and influence of social actors in a given situation, as well as the existence of independent, external structures that affect the actions that these actors can pursue (Wynn and Williams, 2012). Ontologically, critical realism holds that:

1. There is a reality independent of human knowledge or our ability to perceive it.

Experience by humans constitutes only a part of the real world.

2. Reality is made up of stratified domains (Figure 5): the ‘Real’ domain includes all structures and generative mechanisms that endure; the ‘Actual’ includes all events that are generated by mechanisms in the Real domain; and the ‘Empirical’ are those events in the Actual domain that humans experience or observe (Mingers, 2004). Therefore, epistemologically, researchers’ observations of events can lead to theories about the structures and mechanisms that generated them, not as a mirror to reality but as candidate explanations that may suffer from an individual’s bias, misreading and misinterpretation (Danermark et al., 2005: 10). Candidate explanations are thus fallible and socially constructed; they are never final but remain open to further debate and invalidation (Mingers, 2004; Wynn and Williams, 2012).

3. Mechanisms brought about by the power of structures in the Real domain are emergent: they evolve out of complex interactions between the entities that make up reality, including humans. As a result, mechanisms cannot be isolated in experimental conditions or explained by isolated analysis of individual entities. This makes critical realist philosophy suitable when seeking a holistic approach to the explanation of complex phenomena, such as those emerging from an open system like the construction industry.

Figure 5: Critical realist ontology – the nested domains of the ‘Real’, the ‘Actual’ and the ‘Empirical’, after Mingers (2004). The term ‘mechanism’ has incongruous connotations of ‘predictable workings’, but has become a part of the critical realist vocabulary (Easton, 2010). It is therefore used in the thesis, but should not be taken literally.

4. Reality is an open and dynamic system, always in flux. Events are subject to changing contextual conditions, so causation ‘proved’ in one setting or time cannot necessarily be expected to generate the same outcomes in another. Changes through time and in different settings mean it is important always to make explicit the context in which observations are made. Critical realism focuses on explanation rather than prediction (Wynn and Williams, 2012), but thorough explanation of past events may reveal patterns of outcomes. This means that precise outcomes of, for example, proposed policies cannot be predicted; but it is possible to support policymaking by conducting well-informed discussion about potential consequences and applying judgement (Schumacher, 2010).

The goal of critical realist research is thus both more ambitious and more modest than strict positivism: it does not just measure quantifiable properties of phenomena, but has the ambition to understand their nature and question what reality must be like, what underlying mechanisms must exist, for an event to have occurred (Wynn and Williams, 2012). It is modest, though, because explanations are not ‘general laws’, but interpretations of parts of systems and their causal structures. Critical realism holds that humans have an influential role within systems, and as their behaviour, based on private consciousness alongside external factors, cannot be predicted (Schumacher, 2010), research underpinned by positivist assumptions is inadequate to explain system-wide events (Winter, 1989: 29-30).

There are likely to be multiple possible explanations of mechanisms that could have caused any observed outcomes. Not all interpretation is necessarily equal; some explanations are likely to provide better descriptions of the underlying causal structure (Mingers, 2004). Although there is no single correct answer, critical realism attempts to avoid absolute relativism; better or more

valid theories can be identified by ongoing observation, description and debate of ideas (Wynn and Williams, 2012). To contribute to that process, researchers must be explicit about how a particular explanation has been reached, and the ongoing collective mission of critical realist research should be to seek those that are the most useful and plausible.

3.2.3 A pragmatist approach

Approaches to the generation of knowledge are typically categorised as deductive or inductive inference. Deductive enquiry begins from a theory, generates hypotheses to be tested, and conducts tests to establish whether a hypothesis holds true under the studied conditions; then, if necessary, modifies the theory in light of findings. Inductive enquiry begins with specific observations, detects patterns within the data, forms tentative hypotheses, and works towards the development of theory. Thus theory developed inductively is a generalisation of properties found in empirical evidence (Danermark et al., 2005: 89); it is the same type of knowledge. The system of beliefs in critical realism is held to imply a different mode of inference: retroductive, or abductive, enquiry (Wynn and Williams, 2012). Attempts to understand what underlying mechanisms must exist for an event to have occurred do not rely on inference from empirical data. Abductive inference may begin with observation of phenomena, but proceed through intuition and creative thought to conceive new accounts of how events may be related to structures (Danermark et al., 2005: 88-95; Reichertz, 2010). Deductive inference can prove that something in the Empirical domain must be a certain way, while abduction contributes to knowledge by invoking arguments of how structures in the Real domain might be for events in the Actual and Empirical domains to have occurred.

Abduction can thus lead to more novel and far-reaching, albeit qualified, findings. It is seen as complementary to induction and deduction (Tashakkori et al., 1998); the three approaches can be used in combination to balance their respective strengths and weaknesses, and are appropriate during different stages of a research project. Engineering is applied research, and applying research to a world construed as complex and dynamic, in the multi-disciplinary and practical context of construction, calls for an approach that is not dogmatic but sensitive to research needs. Since few research questions are answered neatly using only one process of enquiry, Saunders et al. (2009: 127) emphasise the need for flexibility in approach. A pragmatist mindset was adopted in this project, treating each stage of research as deserving of a tailored approach (Saunders et al., 2009: 109). Thus the research approach and units of analysis vary, and were chosen based on suitability for addressing particular research objectives and likelihood of contributing to the wider project goal (Tashakkori et al., 1998: 26, 30).

In broad terms, Chapters 4 and 5 lead inductively from specific and detailed cases to theory about the existing context of construction waste management, and then proceed abductively to develop notions of how the context could be different and what interventions could create change. Chapter 6 deductively tests these theories in one material group, to verify and validate

the interventions proposed in the earlier chapters. The empirical research thus focuses on two main units of analysis: systems for the recirculation of building components at city-scale, and a specific notional enterprise operating within the urban systems. Beneath that broad framework, the execution of the enquiry created findings on each level that informed the other: the process has been iterative and generated new perspectives by the flicking of focus between urban- and product-scale systems. Table 9 sets out the overall research design and locates these approaches in the three core chapters of the thesis.

Table 9: Research design diagram for core chapters

There is a risk to research quality in attempting to implement complete and repeated iterations of the research process. Doctoral research sometimes avoids this risk by focusing more closely on a single stage (e.g., theory development or empirical observation and explanation); however, given the systemic nature of the problem, it was recognised that there is a need for holistic approaches (section 2.4). It was thus anticipated that addressing the breadth of the research topic would bring greater benefit than pursuing a narrow focus.

The following sections provide a commentary on the research strategy and data collection methods summarised in the lower lines of Table 9.