If keyword research is the foundation of traditional SEO, prompt cluster research is the foundation of GEO. It is the practice of mapping the specific questions that users ask AI tools in your industry, and building content that answers them so directly that AI models cite you as the source.
What Is a Prompt Cluster?
A prompt cluster is a group of semantically related questions that orbit a single topic or intent. Unlike keyword groups (which are typically noun phrases), prompt clusters are complete questions that mirror real user behaviour in AI interfaces.
Example prompt cluster for a business bank account provider:
‘What is the best business bank account for a limited company?’ ‘How do I open a business bank account in the UK?’ ‘Business bank account comparison UK 2026’ ‘Do I need a business bank account if I am a sole trader?’ ‘What documents do I need to open a business bank account?’
Step 1: Use AI Tools to Surface Natural Phrasing
Open ChatGPT, Perplexity, and Google AI Overviews. Type your primary service or product category as both a statement and a question. Study the answers carefully.
Note the exact phrasing of any follow-up questions suggested. In Perplexity, look at the ‘Related’ questions. In Google, look at the ‘People Also Ask’ section. These are directly surfacing the prompt cluster patterns that users are actually using.
Step 2: Use Traditional Keyword Tools for Volume Intelligence
Tools like Ahrefs, SEMrush, and Google Keyword Planner are still valuable for prompt cluster research, used differently. Filter for question keywords (containing who, what, where, when, why, how) in your topic area. These represent the keyword-format version of the same intent.
The overlay between high-volume question keywords and the conversational phrasing you find in AI tools is the sweet spot: questions that users ask in multiple formats and that therefore have the highest GEO opportunity.
Step 3: Mine Community Platforms
Reddit, Quora, and industry forums are where people ask questions in their most natural form. Search your primary topic on Reddit and look at the most upvoted questions in relevant subreddits. Browse Quora for your key topics and note how questions are phrased.
These platforms are AI training data. The questions asked there are very likely to be represented in the prompt patterns AI models have learned.
Step 4: Organise into Clusters and Prioritise
Group your collected questions by underlying intent (not surface keyword). Each group becomes a prompt cluster. Prioritise clusters by:
Business relevance: how closely does this cluster relate to what you sell?
Current AI coverage: is anyone already answering this well in AI tools? If yes, it is harder to displace. If no, it is an immediate opportunity.
Traffic potential: cross-reference with Search Console data to see if related queries are already driving impressions.
Content gap: do you have existing content that could be optimised for this cluster, or does it require new content?