Definition
A grounded answer is one the model justified with retrieved documents. Grounded surfaces (Perplexity, ChatGPT Search, AI Overviews, Gemini with search) cite sources; ungrounded surfaces (default ChatGPT, base Claude) do not. Grounded surfaces respond to SEO investment in days; ungrounded surfaces respond in weeks to months.
Why it matters
Grounding sits in the "Signals & ranking" layer of the AI search stack. Teams that handle it well get cited more, recommended more, and earn more of the AI-mediated revenue in their category. Teams that ignore it spend a year wondering why their content investment never moves the needle inside ChatGPT or Perplexity.
Related terms
- RAG - A technique where an LLM retrieves external documents at inference time and uses them to ground its answer. Powers Perplexity, ChatGPT Search, and AI Overviews.
- AI Overviews - Google's generative-AI answer box at the top of search results, powered by Gemini. Now appears for more than half of qualifying US queries.
- Perplexity - A dedicated answer engine that retrieves the web in real time and synthesises answers with inline citations.
- Citation share - Percentage of cited sources in an LLM answer that come from your domain. Only meaningful on grounded surfaces (Perplexity, ChatGPT Search, AI Overviews).
Apply it
The LLM SEO playbook ties every concept in this glossary into a single operating model. If you want to see how your brand performs across all the LLMs at once - mention rate, citation share, sentiment, rank - start with the free GEO audit or skip straight to a free Livesov account.