Nathan Hall

Who Folds? Brand-blind debate among three commercial AI systems: preregistration

Preregistration, deposited before the main study runs, of a study of brand-blind debate among three commercial AI systems from different companies: OpenAI gpt-6.1-sol, Anthropic claude-sonnet-5-5 and Perplexity sonar-pro (the only one searching the web live). Question: when AI sy...

Discovery, not adoption: crawler retrieval of an llms.txt resource announced through robots.txt, across seven sites on one server, and what a server log can and cannot show

llms.txt is usually evaluated as an un-announced file placed at /llms.txt. I measured a different and narrower question: whether verified or network-attributed crawlers retrieve a Markdown resource when its URL is announced in robots.txt through a Sitemap: directive and in page-l...

Does swapping the Claude API model change which businesses it names from the same search results? A pre-registered same-day A/B of claude-sonnet-4-6 and claude-sonnet-5 on Kansas City AI discoverability questions

Pre-registration, deposited before any study data is collected. Lefty Media Co measures Pick Rate: whether an AI engine names a business when asked who is best. Its Claude measurement calls the Anthropic Messages API with claude-sonnet-4-6 and is scheduled to switch to claude-son...