Impact Evaluation represents the systematic practice of measuring and learning from the outcomes of social, ecological, and economic interventions through participatory and systemic lenses. This domain shifts evaluation from narrow metrics of efficiency or growth toward understanding contribution, vitality, and resilience within living systems — enabling organizations, funders, and communities to make evidence-informed decisions about resource allocation and program design.
The field has developed sophisticated methodologies for capturing social value. Social Return on Investment (SROI), the most widely referenced framework, uses a six-stage process to monetize social outcomes by calculating factors including deadweight (what would have happened anyway), displacement (unintended negative effects), attribution (contributions from other actors), and drop-off (diminishing impact over time). First presented by Emerson and Twersky in 1996 and further developed through UK government funding starting in 2008, SROI enables comparison of different intervention types and helps guide funding decisions toward maximum impact.
Theory of Change (ToC) provides complementary methodology, mapping the logical sequence from inputs to outcomes by defining long-term goals and working backward to identify necessary preconditions. The B Impact Assessment, developed by B Lab, offers a holistic measurement tool for businesses assessing their impact on workers, community, environment, and customers. Key strategies across these methodologies include: engaging stakeholders throughout the process, mobilizing existing operational data, building measurement capacity, and combining qualitative with quantitative approaches.