First Knock helps users see “where I am standing.” But the user’s next question is inevitably “where can I go from here.” Existing AI products respond to this question in two ways, each inadequate: proactive AI gives suggestions the user cannot execute; passive AI only reflects without guiding, leaving the user without any actionable reference. In scenarios where the user actively seeks help, nonintervention design faces the risk of degenerating into moral avoidance—a tension acknowledged but unresolved by the first four papers in this series. This paper proposes “labeled intervention”—a product design principle activated upon the user’s explicit request, where every proactive output is accompanied by a transparent label. This paper does not claim that “labels eliminate manipulation”; rather, it argues that given the inevitability of framing effects in any proactive output, labeled intervention is more ethically defensible than unlabeled intervention—because it at least makes the framing effect perceivable by the user, thereby preserving the user’s capacity for metacognitive resistance. Starting from product requirements, the paper deduces three capability requirements for AI—following the user’s associative leaps, understanding the user’s self-defined causality, and a paradigm-shift in computational power—and takes these as its premises. It then proposes four design principles (responding only to active requests, attaching transparent labels to outputs, matching precision to the user’s current cognitive scale, and returning to silence after withdrawal) and four ethical stop rules (no proactive initiation, no proactive cross-session memory, no strategy adjustment aimed at reducing cognitive effort, and no use of exploration data for model training). The paper explicitly distinguishes “labeled intervention” from nudge theory and reveals its Eastern philosophical origins in the concept of “resonance leading to understanding” (感而遂通) from the Book of Changes. This paper provides a design theory draft—open to discussion, criticism, and revision—for the product that follows First Knock.
