Outcome Harvesting vs Most Significant Change: Which to Use and When

Two participatory, theory-based evaluation methods that do not depend on counterfactual design.

Side-by-Side Comparison

FactorOutcome Harvesting (OH)Most Significant Change (MSC)
Developed byRicardo Wilson-Grau (developed from ~2002, documented 2015)Rick Davies and Jess Dart (2005 guide)
Starting pointObserved outcomes, traced back to attributionStories of change collected from participants
Driven byEvaluator/facilitator, with informant inputParticipants and selection panel members
Output formatStructured outcome statements: description, significance, contribution, evidenceNarrative stories ranked by stakeholder panels
Typical timeline4-8 weeks for the evaluation cycle3-6 months for a full cycle with selection panels
Rigor comes fromExplicit outcome statements, contribution evidence, and substantiation of a transparently selected sampleSelection panels: multi-level filtering by stakeholders who justify their choices
Participant voiceModerate (informant interviews, not participant-authored)High (participants author stories in their own words)
Accountability reporting fitStrong (structured outputs work for donor reports)Moderate (stories need structuring for donor outputs)
Best forComplex/emergent programs, advocacy, systems change, innovationParticipatory programs, empowerment, community-led, unanticipated-change contexts
Facilitator skill requiredHigh (substantiation design, evidence triangulation)High (selection panel design, facilitation across levels)
CostModerate: 30-60% of a standard summative evaluationModerate to high: 40-80% of a standard summative evaluation

For the formal method definitions, see outcome harvesting and most significant change.

What Do Outcome Harvesting and Most Significant Change Have in Common?

Both methods share three foundational features that distinguish them from counterfactual-based evaluation approaches.

Both are theory-based, not counterfactual-based. Neither tries to construct a "what would have happened without the program" comparison. Instead, both ask "what change is observable and how is the program implicated?" This makes both appropriate when counterfactual design is infeasible (small-n, ethical issues, emergent outcomes) or inappropriate (complex programs where no control group is meaningful). See counterfactual and theory-based evaluation.

Both are qualitative-primary. Both work in the language of narrative and description rather than statistics and effect sizes. Both produce outputs that can be supplemented by quantitative data but do not depend on quantitative measurement for their primary findings.

Both emphasize learning alongside accountability. Neither method is a pure compliance tool. Both are designed to produce findings the program can actually use, including unanticipated outcomes that conventional M&E would miss.

These shared foundations mean both methods fit naturally with adaptive management, learning agendas, and theory of change reasoning. See theory of change for the broader framework.

Frequently Asked Questions

What is the difference between Outcome Harvesting and Most Significant Change?

Outcome Harvesting is retrospective and facilitator-led: you start with observed outcomes (from reports, interviews, or records), then work backward to identify program contribution, evidence, and significance. Most Significant Change is story-based and participatory: you collect stories of change from participants, then selection panels at multiple levels choose the stories they consider most significant. Both are alternatives to counterfactual evaluation design. They differ in who drives the process (facilitator vs participants), in pace (weeks vs months), and in output (outcome statements vs narrative stories).

When should I use Outcome Harvesting instead of MSC?

Use Outcome Harvesting when the program is complex or emergent (advocacy, systems change, innovation) and outcomes were not fully predictable at design; when the evaluation needs to move quickly (4-8 weeks is realistic for OH); when contributions from multiple actors need to be disentangled; or when accountability reporting needs structured outcome statements rather than narratives. OH tends to produce cleaner outputs for donor reports but less rich participant voice than MSC.

When should I use MSC instead of Outcome Harvesting?

Use MSC when participant voice and participatory processes matter for the program's theory of change (empowerment programs, community-led programs, programs with strong localization commitments); when unanticipated change is expected and you want a method that captures it; when the evaluation has 3-6 months and can support the multi-stage selection process; or when the learning product is meant to move internal or external audiences who respond to narrative. MSC produces richer qualitative data but takes longer and requires more facilitator skill in selection design.

Can you use Outcome Harvesting and MSC together?

Yes, and some programs do. Common combination: MSC for story collection from participants and frontline staff, then OH's outcome-statement framework to synthesize and structure the stories into evaluable outcomes with significance, contribution, and evidence. The combined approach captures participant voice (MSC strength) and produces accountability-ready output (OH strength). Cost is higher than either alone, roughly 1.3-1.6x versus a single method.

Are OH and MSC considered rigorous enough for donor reporting?

Acceptance depends on the actual evaluation questions, terms of reference, and applicable agreement. Explain why the method fits, how outcomes or stories are selected and checked, and what causal or population claims it cannot support. Do not imply donor approval or treat either method as a shortcut to a counterfactual effect estimate.