We reflect on how qualitative research can be used to develop or refine theories about how the mechanisms triggered by intervention enactment might generate outcomes, referring to examples from a ‘realist trial’ of a whole-school health intervention. Qualitative research can explore mechanisms directly, by asking participants how they think interventions work, or indirectly, by exploring participant experiences of intervention-related actions to understand the conditions and consequences of these actions. Both of these approaches can inform theorisation of how mechanisms are triggered and generate outcomes, and how this is contingent on context. We discuss methods for sampling, data collection and data analysis, and recommend dimensional analysis as a means to analyse qualitative data on mechanisms. We then consider how to draw on qualitative research to inform hypotheses to be tested statistically.
AstburyBLeeuwFL (2010) Unpacking black boxes: Mechanisms and theory building in evaluation. American Journal of Evaluation31(3): 363–81.
2.
BarnesMMatkaESullivanH (2003) Evidence, understanding and complexity: Evaluation in non-linear systems. Evaluation9: 265–84.
3.
BonellCAllenEWarrenE, et al. (2018) Initiating change in the school environment to reduce bullying and aggression: A cluster randomised controlled trial of the learning together (LT) intervention in English secondary schools. The Lancet392(10163): 2452–64.
4.
BonellCFletcherAMortonM, et al. (2012) ‘Realist randomised controlled trials’: A new approach to evaluating complex public health interventions. Social Science and Medicine75(12): 2299–306.
5.
BonellCJamalFHardenA, et al. (2013) Systematic review of the effects of schools and school environment interventions on health: Evidence mapping and synthesis. Public Health Research1(1): 1–320.
6.
BonellCProstAMelendez-TorresGJ, et al. (2021) Will it work here? A realist approach to local decisions about implementing interventions evaluated as effective elsewhere. Journal of Epidemiology and Community Health75(1): 46–50.
7.
BreuerELeeLDe SilvaM, et al. (2016) Using theory of change to design and evaluate public health interventions: A systematic review. Implementation Science11(1): 63.
8.
BurchettHEDKnealeDBlanchardL, et al. (2020) When assessing generalisability, focusing on differences in population or setting alone is insufficient. Trials21(1): 286.
9.
CareyRNConnellLEJohnstonM, et al. (2019) Behavior change techniques and their mechanisms of action: A synthesis of links described in published intervention literature. Annals of Behavioral Medicine53(8): 693–707.
CohnSClinchMBunnC, et al. (2013) Entangled complexity: Why complex interventions are just not complicated enough. Journal of Health Services Research & Policy18(1): 40–3.
12.
DaveyCHassanSCartwrightN, et al. (2019) Designing Evaluations to Provide Evidence to Inform Action in New Settings. London: Department for International Development.
13.
FalletiTGLynchJF (2009) Context and causal mechanisms in political analysis. Comparative Political Studies42(9): 1143–66.
14.
GardnerFBurtonJKlimesI (2006) Randomised controlled trial of a parenting intervention in the voluntary sector for reducing child conduct problems: Outcomes and mechanisms of change. Journal of Child Psychology and Psychiatry47(11): 1123–32.
15.
GiddensA (1984) The Constitution of Society. Cambridge: Polity Press.
16.
HawePShiellARileyT (2004) Complex interventions: how ‘out of control’ can a randomised controlled trial be?British Medical Journal328: 1561–63.
17.
HedstromPSwedbergR (1998) Social Mechanisms: An Analytical Approach to Social Theory. Cambridge: Cambridge University Press.
18.
HoddyE (2018) Critical realism in empirical research: Employing techniques from grounded theory methodology. International Journal of Social Research Methodology22: 111–24.
19.
LacoutureABretonEGuichardA, et al. (2015) The concept of mechanism from a realist approach: A scoping review to facilitate its operationalization in public health program evaluation. Implementation Science10: 153.
20.
LemireSKwakoAJNielsenSB, et al. (2020) What is this thing called a mechanism? Findings from a review of published realist evaluations. New Directions for Evaluation167: 73–86.
21.
ManzanoA (2016) The craft of interviewing in realist evaluation. Evaluation22(3): 342–360.
22.
MarchalBvan BelleSvan OlmenJ, et al. (2012) Is realist evaluation keeping its promise? A review of published empirical studies in the field of health systems. Evaluation18(2): 192–212.
23.
MarkhamWAAveyardP (2003) A new theory of health promoting schools based on human functioning, school organisation and pedagogic practice. Social Science & Medicine56(6): 1209–20.
24.
MarmotMG (2004) Status Syndrome: How Your Social Standing Directly Affects Your Health and Life Expectancy. London: Bloomsbury Publishing.
25.
MayC (2013) Towards a general theory of implementation. Implementation Science8: 18.
26.
Melendez-TorresGJWarrenEVinerR, et al. (2021) Moderated mediation analyses to assess intervention mechanisms for impacts on victimisation, psycho-social problems and mental wellbeing: Evidence from the INCLUSIVE realist randomized trial. Social Science and Medicine279: 113984.
27.
MooreGAudreySBarkerM, et al. (2014) Process Evaluation of Complex Interventions: UK Medical Research Council (MRC) Guidance. London: MRC Population Health Science Research Network.
28.
MooreGFEvansRE (2017) What theory, for whom and in which context? Reflections on the application of theory in the development and evaluation of complex population health interventions. Social Science and Medicine Population Health3: 132–35.
29.
OliverC (2011) Critical realist grounded theory: A new approach for social work research. British Journal of Social Work42(2): 371–87.
30.
PawsonR (1996) Theorizing the interview. British Journal of Sociology47(2): 295–314.
PorterS (2015) The uncritical realism of realist evaluation. Evaluation21(1): 65–82.
33.
SayerA (2000) Realism and Social Science. Thousand Oaks, CA: SAGE.
34.
SchatzmanL (1991) Dimensional analysis: Notes on an alternative approach to the grounding of theory in qualitative research. In: MainesDR (eds) Social Organization and Social Process: Essays in Honor of Anselm Strauss. New York: Aldine De Gruyter.
35.
SchützA (1962) The Problem of Social Reality: Collected Papers I. Leiden: Martinus Nijhoff.
36.
SkivingtonKMatthewsLSimpsonS, et al. (2021) A new framework for developing and evaluating complex interventions: Update of Medical Research Council guidance. British Medical Journal374: n2061.
37.
ThirskLMClarkAM (2017) Using qualitative research for complex interventions: The contributions of hermeneutics. International Journal of Qualitative Methods16: 1–10.
38.
UnrauYA (2001) Using client exit interviews to illuminate outcomes in program logic models: A case example. Evaluation and Program Planning24: 353–361.
39.
Van UrkFGrantSBonellC (2016) Involving stakeholders in programme theory specification: Discussion of a systematic, consensus-based approach. Prevention Science12(14): 541–57.
40.
WarrenEMelendez-TorresGMVinerRM, et al. (2020) Using qualitative research within a realist trial to build theory about how context and mechanisms interact to generate outcomes: Findings from the trial of the Learning Together whole-school health intervention. Trials21: 774.
41.
WarrenEOpondoCAllenE, et al. (2019) Action groups as a participative strategy for leading whole-school health promotion: Results on implementation from the INCLUSIVE trial in English secondary schools. British Education Research Journal45(5): 748–62.
42.
WilkinsonRPickettK (2009) The Spirit Level: Why More Equal Societies Almost Always Do Better. London: Allen Lane.
