Percentage of topically relevant AI responses that correctly cite your entity. Measure through query sampling across identity, domain, and vocabulary perimeters. Sample 20-30 queries per perimeter quarterly. Target: ≥75% per perimeter for Full Spectrum Dominance. Below 50% indicates sub-threshold position. Test across multiple AI systems (ChatGPT, Claude, Perplexity, Gemini). Track quarterly as leading indicator of schema entropy. Degrading attribution rate signals maintenance lapse before it appears in other metrics.