From Behavioral Design to Behavior-Based Design: Functional Specification for Designed Environments

Behavioral design has developed frameworks and taxonomies that help researchers and practitioners organize, select, and describe interventions. However, identifying an intervention technique does not establish the functional relations through which it influences behavior. This article proposes behavior-based design (BBD) as a programmatic approach that places functional specification at the center of the design process. BBD does not introduce new behavioral principles or replace established methods of behavior analysis. Instead, it organizes their application to deliberately designed environments, including digital interfaces, public services, sustainability initiatives, and organizational systems. The article identifies five criteria for adequate functional specification: behavioral precision, functional coherence, discriminability among alternative functional explanations, relevance to design decisions, and empirical accountability. Examples illustrate how the same intervention category may involve different functional relations, leading to different predictions, measurement strategies, and design decisions. Particular attention is given to competing contingencies, maintenance, generalization, and the conditions affecting those responsible for implementing and sustaining interventions. Finally, the article outlines a research agenda for comparing designs informed by explicit functional hypotheses with approaches relying primarily on broader intervention categories. The proposed contribution of BBD is therefore methodological and programmatic: to make functional specification an explicit requirement of design and to evaluate its predictive and practical value through cumulative empirical research.