What is Grounding?
Connecting a language model's answer to retrieved real-world sources at answer time, reducing hallucination and creating the citation opportunity.
Definition
Grounding is the technique of anchoring a model's output to retrieved evidence — live web pages, documents, or a search index — rather than letting it answer purely from training memory. Grounded answers quote and cite; ungrounded answers reconstruct from statistical memory and can hallucinate.
Google explicitly calls this “grounding with Google Search” in Gemini; ChatGPT Search and Perplexity are grounded by design.
Why it matters
Grounding is the mechanism that makes GEO actionable in real time. Training-data visibility takes months and model releases to change; grounded retrieval reads your page today. A page published this week can be cited this week if it's crawlable and answers the prompt. It also splits your strategy in two: be present in training data (long game) and win retrieval (fast game).
Frequently asked
How do I know if an answer about my brand was grounded?
Citations are the tell. If the assistant links sources, retrieval happened; if it answers from memory with no links, you're seeing training-data knowledge — accurate only as of the model's cutoff.
Does grounding eliminate hallucination?
Reduces, not eliminates. Models can still misread retrieved pages or blend memory with evidence — which is why monitoring what assistants actually say about you matters.
Related terms
- Generative Engine Optimization (GEO)The discipline of increasing a brand's visibility inside AI-generated answers — the successor field to SEO for the AI search era.
- GPTBotOpenAI's web crawler for collecting model training data. Distinct from OAI-SearchBot, which powers live ChatGPT Search retrieval.
- AI CitationsThe linked sources an AI assistant credits when generating an answer. Being cited is the AI-era equivalent of ranking #1.
- AI CrawlerBots operated by AI companies — GPTBot, ClaudeBot, PerplexityBot, Google-Extended — that fetch web content for model training or live answer retrieval.