Ahrefs' Xibeijia Guan Tops 2026 Ranking of AI Search Researchers

Ahrefs data scientist Xibeijia Guan has published 31 original AI search studies since 2023, second only to Growth Memo's Kevin Indig, whose 36 studies top a new ranking of AEO and GEO researchers. The list, built from an audit of more than 17,000 pages published since January 2023, credits Guan with the field's most-linked study: a finding that AI Overviews reduce clicks by 34.5%, which has earned 7,681 referring domains and 16,314 backlinks.

How the ranking was compiled

The compiler started with a longlist of 87 names recommended as AEO/GEO experts or working as researchers at AI visibility companies. Every page on each person's main publishing sites since 2023 was checked against four criteria:

• Original data collected or analyzed by the author or their team
• Focus on AI search — ChatGPT, Perplexity, Gemini, Claude, Copilot, Grok, AI Overviews or AI Mode
• A meaningful sample: roughly 50+ prompts, queries or pages; analytics from 10+ sites; 100+ survey respondents; or a described controlled experiment
• A published write-up between January 2023 and November 2026

Only studies carrying a byline, co-author credit or named analyst counted. Anonymous company research scored zero. Ranking used study counts, with ties broken by linking websites.

Who leads, and what the numbers show

Indig, previously head of SEO and growth at Shopify, G2 and Atlassian, leads with 36 studies on growth-memo.com and partner sites. His most-linked work includes "The science of how AI pays attention" with 447 referring domains, and the first UX study of Google's AI Overviews, cited by 300 domains.

Dan Petrovic of DEJAN ranks third with 20 studies. His server-log research found Google, Anthropic and OpenAI crawlers fetched dejan.ai's robots.txt 1,150 times in 30 days, but its llms.txt only 4 times. Louise Linehan of Ahrefs follows with 19 studies, including a finding that 97% of llms.txt files across 137,210 domains never get read, and a test where 1,885 pages that added schema saw barely any change in AI citations.

What the top research actually found

The ranked studies cover the discipline's defining questions — click losses, citation behavior, and measurement.

• Johannes Beus (SISTRIX, 14 studies) documented AI citation drift and German click-through rate drops.
• Manick Bhan (Search Atlas, 13 studies) analyzed 120M+ citations across 6.4M domains, finding LLM citations only loosely tied to Google rankings and no measurable effect from schema or llms.txt.
• Davis McCain (Profound) found the half-life of an AI citation is 11 days, based on a 1.19 million page-engine analysis across 7 AI engines.
• Chris Long (Nectiv) measured ChatGPT's fan-out queries rising to 7.61 per prompt, against Google's average of 9.06, using 7B+ log files.
• Aleyda Solís (Orainti) found third-party sources drive 84% to 93% of AI citation weight for SaaS brands, and AI search is only 0.19% of visits across 40 sites.
• Andy Crestodina (Orbit Media) reported AI visitors convert to leads at 3x the rate of other organic traffic across 97 B2B websites and 29 million visits.
• Ross Hudgens (Siege Media) found five or more homepage credibility statements lifted AI visibility 62% for mid-authority brands in a 585-brand study.

Rand Fishkin (SparkToro, 4 studies) contributed two of the ten most-linked studies: one showing AI tools are highly inconsistent when recommending brands (3,153 referring domains), and one estimating Google handles about 373 times more searches than ChatGPT.

Which studies won the most links

Ahrefs dominates the link table. Guan and Ryan Law's 34.5% click-reduction study (April 2025) leads. Guan and Linehan hold four of the top seven slots, including the 75,000-brand AI Overview visibility analysis (4,879 referring domains) and an update showing 38% of AI Overview citations pull from Google's top 10. David Bell's Previsible report that AI traffic rose 527% rounds out the top ten.

The list spans tool vendors (Ahrefs, SISTRIX, seoClarity, Moz), agencies (Siege Media, Snippet Digital, Graphite) and independent researchers. Full 25-name coverage includes Josh Blyskal and McCain at Profound, Metehan Yeşilyurt and Tomek Rudzki at Peec AI, Tom Capper at Moz/STAT, Lily Ray at Amsive, Hanns Kronenberg at GPT Insights, Mark Traphagen at seoClarity, Mitul Gandhi at seoClarity, and Jan Ehrlinspiel at Peec AI.

For teams tracking AI visibility, the ranking doubles as a research pipeline: the named studies are the primary evidence base for citation behavior, traffic impact and measurement methodology through November 2026, and their follow-up work is what to monitor as AI Overviews, AI Mode and ChatGPT search continue to shift referral patterns.