Assess learners' ability to analyze the structure and common failure modes of habit-formation systems—components (cues, routines, rewards), feedback loops, context dependence, and points of friction—and to design robust, individualized behavior-change strategies. Tasks include diagnosing why a system failed, proposing targeted design fixes (e.g., habit-stacking, friction management, adaptive rewards, monitoring), specifying personalization and measurement approaches, and evaluating trade-offs and ethical considerations for sustained change.