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Realist Evaluation

Realist Evaluation
Also known as: Realist evaluation、CMO analysis

Examine for whom, under what circumstances and why change occurs through hypotheses linking context, mechanisms and outcomes. Explore why the same program produces different results. [1]

Realist evaluation CMO worksheet — openReferences and checked sections
Difficulty
Advanced
Cost
High
Duration
Illustrative estimate (adjust for scale and staffing): 2–4 weeks for literature review and CMO hypotheses; several months to 1 year or more for empirical work
Content updated: 2026-09-13Source checked: 2026-09-13 (includes AI cross-checking)No documented human reviewIncludes fictional examples

How it works at a glance

Realist evaluation examines people’s responses to resources and opportunities provided by a program. Develop hypotheses linking context (C), mechanism (M) and outcome (O), and examine them using cases and data from different conditions. [1]

A mechanism is not an activity label; it combines opportunities provided with participants’ interpretations and responses. Use analytical findings to revise initial hypotheses and specify conditions needed for implementation elsewhere. [1]

ContextContext / conditions＋MechanismMechanism＝OutcomeOutcomeDevelop and test CMO hypotheses: what works, for whom, and in which circumstances?Programs offer opportunities; outcomes arise through participants’ reasoning
Examine the hypothesis that a mechanism (M), operating in a context (C), leads to an outcome (O). The diagram’s symbols express conceptual relationships, not an arithmetic formula.

When to use it and when it is unsuitable

When to use it

  • Explaining why a program worked in one setting but not another
  • Assessing transferability when considering implementation or scaling in different contexts
  • Systematically learning about effective mechanisms from existing evaluations and studies (realist synthesis)
  • Refining program theory and improving intervention design

When it is unsuitable

  • When proving average intervention effectiveness is the purpose rather than explaining mechanisms; RCT or DiD is appropriate
  • When prior knowledge and literature are insufficient for CMO hypotheses and exploratory research is needed first

Participants, roles, and deliverables

Participants and roles

Evaluation researchers (consider expertise in both quantitative and qualitative approaches), program theory specialists and frontline implementers. An illustrative plan assigns literature review to 1–2 researchers.

Main deliverables

  • CMO hypothesis map
  • Refined CMO configuration list
  • Analysis of effects by context
  • Transferability and adaptation conditions report

Implementation steps

  1. Reframe research questions as CMO questions
    Reframe “Does this program work?” as “In what contexts, through which mechanisms, and with what outcomes?” This determines the overall evaluation direction.
  2. Develop initial CMO hypotheses
    Use literature, previous evaluations and implementer interviews to propose several CMO configurations. State them as “If this mechanism operates in this context, this outcome is expected.”
  3. Design data collection
    Design collection to examine and revise each CMO element. Include contextual variables, proxies for mechanisms such as cognitive or emotional change, and diverse outcomes.
  4. Test and refine CMO hypotheses
    Compare data with hypotheses to analyze whether C → M → O holds and in which contexts it does not. Repeatedly revise, reject and refine hypotheses.
  5. Refine configurations and assess transferability
    Summarize tested and refined configurations and identify contexts where mechanisms operate. Specify transferability and necessary adaptations.
  6. Recommend policy and practice changes
    Use CMO analysis to recommend contexts for implementation and what is needed for mechanisms to operate.

Strengths and limitations

Strengths

  • Explaining mechanisms provides deeper understanding of why something works beyond whether it works
  • Analyzing context specificity can reduce failure risks during scaling or transfer
  • Applies rigorous causal thinking to complex social interventions where RCTs are difficult

Limitations

  • CMO hypothesis development requires advanced conceptual and theoretical skills
  • Empirically measuring mechanisms is difficult and relies heavily on proxies
  • Unsuitable for explaining average-effect estimates to donors seeking numbers

Common pitfalls

  • Being satisfied with a CMO configuration and neglecting data collection to test it
  • Confusing mechanisms with program activities such as delivering training. Mechanisms involve reasoning and resources in relation to the program (participants’ cognition, emotions and choices)
  • Using only broad categories such as urban / rural rather than identifying specific contextual factors affecting mechanisms

Conditions of use and evidence

  • Consider mechanisms as combinations of program resources or opportunities and people’s responses to them. [1]
Fictional example; not actual results

Checking conditions for applying training at work

The following fictional example compares organizations that did and did not use plans after evaluation planning training.

Hypothesis numberContext (contextual conditions)Mechanism (changes in cognition, emotions or choices)Outcome (expected result)Rationale and sources
H1Improvements can be proposed at regular meetingsSeeing the training draft creates confidence that it can be explainedStaff bring the plan to a meeting and determine itemsUntested hypothesis for this example

Common errors in judgment

Common mistake

Writing “2 training sessions delivered” under M

How to revise

Describe how exercises affected participants’ judgments

ReasonThis distinguishes implementation activities from mechanisms.

Common mistake

Applying one successful organization’s CMO to all organizations

How to revise

Examine different conditions and non-use cases and revise hypotheses

ReasonThe method examines how responses vary by context.

Organize your thinking by writing

Realist evaluation CMO worksheet

A practical template is available to fill in and print on A4 paper.

Open worksheet

Related methods

Contribution AnalysisProcess TracingTheory of ChangeDevelopmental EvaluationQualitative Comparative Analysis

References and checked sections

  1. Supplementary Guide: Realist evaluation
    HM Treasury / Evaluation Task Force · 2026
    Section consulted
    3. Developing realist theory: Context, mechanism and outcome; 5. Applying the realist frame to evaluation
    How it relates to the text
    Consider mechanisms as combinations of program resources or opportunities and people’s responses to them.
    Source checked: (includes AI cross-checking)

Editorial and checking information

Content updated: Source checked: (includes AI cross-checking)No documented human reviewIncludes fictional examplesEditorial policy and scope of checkingCite this pageReport a correction

How to cite this page

EvalCompass Editorial Team. “Realist Evaluation”. EvalCompass, updated 2026-09-13. https://evalcompass.jun-nakatani.com/en/methods/realist-evaluation/
Add the date you accessed the page. Text created by this site is available under CC BY 4.0. Quotations, external materials, and bundled fonts have their own terms of use. When reusing content, credit the source, link to the license, and indicate any changes.

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Change history
  • — Updated explanations to correspond to the sources and added method-specific fictional completed examples, judgment examples and a change log.