WITHDRAWN

Speech is humanity's strongest coordination technology, yet we rarely treat it as an engineered system.This thesis reframes speech as a toolchain-Intention Compilation Actuation Feedback-and proposes Return on Expression (RoE), the realized state change per unit cost, as the organizing objective.We present (i) a formal state-space/control model of utterances as interventions on beliefs, goals, and commitments; (ii) an empirically calibrated affordance map that translates context variables (uncertainty, risk, expertise asymmetry, channel constraints) into design choices (framing, redundancy, prosody); (iii) a failure taxonomy with detectable signals and mitigation protocols; and (iv) a Speech IDE that instruments conversation with an LLM-in-the-loop intention compiler, ambiguity linters, a commitment type checker, and a grounding meter.We define standardized micro-protocols (e.g., Query Calibrate Commit; Goal Constraint Offer Check) and preregistered experiments across lab and field settings to estimate treatment effects on RoE, commitment conversion, grounding depth, and rework.Bayesian hierarchical models support estimation and transportability across domains.Ethics features (consent-to-influence, bias audits, kill-switches) reduce misuse.If validated in preregistered A/B tests (20% CCR lift and 25% ambiguity-error reduction), this framework provides a measurable, reproducible way to teach speech as a craft-raising coordination reliability in education, healthcare, and operations while establishing RoE as a first-class design objective.