The AEO measurement pyramid recommends grounding every reporting cycle in layer-one search performance data. Why is this the anchor point instead of AI-specific metrics in layer two?

Search performance data serves as the anchor point because it represents the most stable and complete dataset available for understanding audience behavior and content effectiveness. This foundational data provides a reliable baseline against which all other performance metrics, including AI-specific ones, can be accurately measured and interpreted. While AI visibility data offers valuable insights, it is often newer, less standardized, and can fluctuate more, making it less suitable as an initial anchor. Presenting exciting data is not the primary goal; accuracy and reliability are. There is no technical requirement from Google tying layer-one reporting to AI feature access.