The Proof of the Pudding: Introducing quantitative testing in transition design reasoning

The urgent challenges of climate change, inequality, and declining societal well-being highlight the inadequacies of existing systems to meet sustainability goals. Transition design—a field at the intersection of design, sustainability science, and transition studies—has emerged as a response to these systemic issues. Despite growing interest in its practice, there remains a gap in understanding transition design processes, particularly regarding the effectiveness of resulting interventions in fostering systemic change. This study addresses this gap by proposing a conceptual framework that connects five essential transition design activities—navigating scales from micro to macro-level systems; considering temporality from the present to far future; engaging and repositioning actors from individuals and groups to networks; framing and designing from single solutions to portfolios; and practising reflexivity from activities to outcomes—to three evaluative qualities for its outcomes: desirability, plausibility, and networkedness of interventions. Using this framework, we assessed a portfolio of 21 proposed interventions that were designed to transition the Dutch food system to reduce food waste. Each intervention was presented as a drawing of a product-service system and was accompanied by a narrative of a user engaging with the intervention. The interventions were evaluated by consumers, companies, and experts through an embedded mixed-methods approach in which quantitative research was complemented by qualitative insights. Our findings reveal that while consumers and companies tend to favour near-future interventions that adapt existing food consumption practices, experts prefer long-term interventions that disrupt existing practices. Additionally, the results indicate that primarily quantitative evaluations may not sufficiently capture the complex, systemic qualities of transition design interventions, suggesting a need for a more balanced mixed-methods approach that incorporates context-sensitive insights. We conclude by reflecting on avenues for methodological development to improve evaluation as a (reflexive) transition design activity.