The percentage of AI responses in which the entity is correctly identified and cited when topically relevant — the core measurement of entity infrastructure effectiveness. Measured by sampling category-relevant queries, having multiple AI systems respond, and calculating what percentage of responses correctly attribute the entity. An entity attribution rate below 50% indicates the entity has not yet crossed the confidence threshold for that category. Attribution rate is measured per-perimeter: identity attribution, domain attribution, and vocabulary attribution are independent and must be tracked separately.