Princeton-led study proposes standard metrics for generative search attribution

A preprint from researchers at Princeton and industry collaborators defines two metrics aimed at standardizing GEO measurement across platforms.

Generative Impression (GI) — Counted when a brand URL appears in the cited source set of an AI answer, weighted by answer impression estimates.

Citation Half-Life (CHL) — Median days until a URL drops out of top-3 citation slots for a fixed prompt set — analogous to SERP decay curves.

The authors note that FAQ and schema completeness explain 34% of variance in CHL in their 8,000-prompt corpus. Visora incorporates compatible proxies in Monitor dashboards for Pro users.