Technical Explainer

How AI Search Works — RAG, Training, and What It Means for Your Brand

To optimise for AI search, you need to understand how AI search actually works. This explainer covers the mechanics — and translates them into practical implications for your brand.

Track your brand in AI search

The difference

Traditional search vs AI search

Traditional search (Google pre-AI)

  • ·Crawls and indexes pages by keyword relevance
  • ·Returns a ranked list of 10 results
  • ·User clicks through to find their answer
  • ·Success = high ranking, high CTR
  • ·Signals: backlinks, on-page keywords, page authority
  • ·Optimised by: SEO — title tags, link building, content

AI search (ChatGPT, Perplexity, AI Overviews)

  • ·Generates a synthesised answer from multiple sources
  • ·Returns one answer — often with 2–5 citations
  • ·User gets the answer without clicking
  • ·Success = appearing in the answer and citations
  • ·Signals: entity consistency, direct answers, schema, authority
  • ·Optimised by: AEO — structured content, entity signals, schema

The two paradigms are not mutually exclusive — strong traditional SEO creates foundations that benefit AI search visibility. But AI search requires additional, specific optimisations that have no precedent in traditional SEO. A brand can rank #1 on Google and be completely invisible in ChatGPT.

The mechanics

How LLMs retrieve information

Large language models draw from three distinct information sources. Understanding each one tells you where to focus your optimisation effort.

Training data

The model's base knowledge

How it works

During pre-training, LLMs ingest vast quantities of web content — articles, documentation, forum posts, news. Brands, products, and concepts that appear frequently, consistently, and accurately in that training corpus become part of the model's base knowledge. This knowledge is static until the model is retrained.

What to do

To influence training data signals: build consistent, authoritative content published across many sources over time. Wikipedia mentions, press coverage, and well-linked documentation all contribute.

RAG (Retrieval-Augmented Generation)

Real-time web retrieval

How it works

Many modern AI systems — including Perplexity, ChatGPT with web browsing, and Google AI Overviews — use RAG: they fetch current web pages at query time, extract relevant passages, and incorporate them into the generated answer. This is more dynamic than training data and can be influenced by current on-page content.

What to do

To perform well in RAG: ensure key pages are crawlable by AI agents (check robots.txt), load fast, and contain direct answers to target questions. Structured data and clear semantic HTML improve extraction quality.

Fine-tuning and RLHF

Human preference training

How it works

Models are refined using Reinforcement Learning from Human Feedback (RLHF) — human raters evaluate responses, and the model learns to prefer answer styles that humans rate as accurate, helpful, and trustworthy. This shapes which types of content and sources the model gravitates toward.

What to do

High-quality, trustworthy, well-cited content performs better because it matches the response style RLHF training reinforces. Thin, marketing-heavy content without supporting evidence is deprioritised.

Signals

What makes a brand AI-discoverable

AI-discoverability is not random. The brands that appear consistently in AI answers share a set of common signals — most of which can be deliberately built.

SignalWhat it meansImpact
Consistent entity descriptionYour brand name, product description, and positioning are described the same way across your website, press coverage, G2, Crunchbase, and social profiles.High
Direct answer contentPages that answer specific questions in the first 1–2 sentences — without preamble — are more extractable by RAG systems.High
FAQ schema markupExplicit question-answer structured data makes it trivial for retrieval systems to identify what question a piece of content answers.High
Third-party citationsMentions in press, analyst reports, review sites, and well-linked blog posts signal that your brand is real and worth referencing.High
AI crawler accessibilityOAI-SearchBot, PerplexityBot, and ClaudeBot must be able to crawl your site. Blocking them in robots.txt removes you from RAG retrieval.Critical
Original data and researchStatistics and research that can only be sourced back to your brand create citation dependencies — other content will reference you, strengthening your signal.Medium
Review site presenceG2, Capterra, Trustpilot, and category-specific review sites are frequently cited by AI when discussing software categories.Medium
Page load speedRAG systems fetch pages in real time. Pages that load slowly or block rendering impair content extraction.Medium

Measurement

Knowing your current AI visibility

Understanding how AI search works is the first step. The second step is knowing where your brand actually stands — right now — across the AI platforms your customers use.

Without measurement, you are flying blind. You might be investing in content that AI systems never cite, missing obvious gaps that competitors have already filled, or unaware that AI is describing your product inaccurately.

  • Which AI platforms mention your brand?
  • How often vs competitors?
  • Is the description accurate?
  • Which questions do you appear in vs which ones you're absent from?
  • Which of your pages are being cited?

Surfaceable answers all of these

Surfaceable is purpose-built AI visibility monitoring. We run daily automated queries across ChatGPT, Perplexity, Claude, Gemini, and Grok — giving you the data you need to understand your AI search presence and improve it systematically.

  • Daily queries across 5 AI platforms
  • Competitor share of voice comparison
  • Answer accuracy monitoring
  • Citation source tracking
  • Topic coverage reports
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