Table 4.

Meta-narratives on case study, context and complex intervention identified in the empirical literature

	Meta-narrative #1: Case studies develop and test complex interventions [40–49]	Meta-narrative #2: Case studies analyse change in organisations [50–54]	Meta-narrative #3: Case studies are appropriate for conducting realist evaluation [55–60]	Meta-narrative #4: Case studies enable naturalistic study of complex change [61–65]
Epistemological assumptions	Positivist	Positivist or critical realist	Social realist (realist evaluation)	Interpretivist, critical realist
Case study approach	Procedural – case study as enabling testing of complex interventions in ‘real life’ contexts	Recursive - in-depth study in which theory and data are mutually reinforcing	Structured - interrogating how mechanisms triggered in specific contexts lead to particular outcomes	Iterative - naturalistic, emergent, reflexive, and using theory-building to surface complexity
Data collection methods	Main phase predominantly quantitative. Qualitative methods used to develop the intervention and provide triangulation	Purposive collection of qualitative and quantitative data to build and test theory	Semi-structured interviews to surface theories of change to guide collection and analysis of qualitative and quantitative data to explore these	Predominantly qualitative, with strong anthropological emphasis (e.g. ethnography) and high degree of researcher reflexivity
Approach to theorisation	Seeking to identify contextual factors that affect intervention outcomes, and measure their contribution	Developing and extending middle-range or programme theory about the forces that drive change in organisations.	Developing middle-range or programme theory, perhaps expressed as context-mechanism-outcome (CMO) relationships	Rich description of the case is foregrounded with use of substantive theory to inform and extend analysis
How complexity is articulated	Mechanistically, as multiple mediators and moderators of the effect of the intervention	Dynamically: the system is seen as evolving over time	Generatively, as an intervention triggers different mechanisms in different contexts	Narratively, as the non-linear unfolding of events and actions, including adaptation to change
How context is conceptualised	Characteristics of the implementation setting or human factors impacting the intervention	Dynamic organisational, policy or human backdrop, changing over time as the intervention is implemented	Set of circumstances where particular mechanisms are triggered to produce particular outcomes	Emergent and co-shaped through relationships and wider social influences on implementation practices
Analytic approach	Primarily deductive, applying frameworks to aggregate data from multiple sources	Comparative logic of analysis; sometimes informed by a priori themes from earlier phases of case study	Retroductive logic, centred around context-mechanism-outcome formations	Iterative, involving reflexivity, interpretation, multiple kinds of data synthesis and (sometimes) dialogue with theory
Basis for transferability	Theoretical replication	Primarily interest is in the case/s, may develop middle-range theory	Identification of (generative) causal relationships: demi-regularities	Naturalistic or theoretical generalisation
Outputs style	Typically, a structured academic paper, including a diagrammatic model of links between intervention and outcome	Varied, but often narratively as a long and discursive report. Some are more structured, offering a series of hypotheses that have been tested	Methodological narrative which sets out how different configurations of context and mechanism were systematically tested and confirmed or rejected	Rich case narrative which highlights the unique detail of the case and may use literary devices (e.g. metaphor, surprise) to create a compelling story