An AI answer does not send people to your page. It lifts a passage from it, rewrites that passage in its own words, and attaches a link if you are lucky.
That one fact changes what answer engine optimisation is. The unit you are optimising is no longer the page. It is the paragraph.
Most UK service pages were written for the old unit. They open with a paragraph about the firm, describe the service in the middle, and put the useful fact (price, time, who qualifies) near the bottom, if at all. Retrieval systems score each passage on its own, and a passage that only makes sense in context scores badly.
Google has ranked individual passages since 2021
Google started ranking individual passages on 10 February 2021, and said at the time that the change would affect about 7% of queries. It had announced the change at its Search On event in October 2020, with this description of the problem:
"Sometimes the single sentence that answers your question might be buried deep in a web page."
Google, Search On 2020 announcement, October 2020
The fix, in Google's words, was to understand "passages in addition to the relevancy of the overall page". Google also said that websites did not need to change anything for the update.
That was true for classic blue links, where the passage system only helped when a good answer was hidden inside an otherwise unrelated page. Five years on, the passage is what gets shown and the page is what gets credited.
Generative answers are assembled from passages
Google's own guide to generative AI features describes a two-step process: retrieve pages, then pull the specific information out of them. The May 2026 guide, updated in July, says the systems "retrieve relevant, up-to-date web pages from our Search index" and then "review the specific information from those retrieved pages to generate a more reliable and helpful response".
The retrieval step still works at page level, which is why the guide insists that ordinary SEO still matters. The second step is where your page stops being a page. The model reads the retrieved text in sections, picks the sentences that answer the question, and writes them into the response.
Query fan-out multiplies this. One question about weeds becomes several searches about herbicides and prevention, and each sub-question wants its own passage.
The LLM Pulse GEO guide, updated in October 2026, lists "passage-level extractability (clean structure, short factual statements, attributable quotes)" among the things generative engines look for, and says the model "will scan for a sentence that directly answers the user's question and lift it."
That is a vendor's working description, not a published measurement. It does match Google's own account, and what we see when we test prompts against client pages.
This is already most UK searches, not a future problem
About 30% of Google searches in the UK now show an AI overview, according to Ofcom's December 2025 report, and 53% of adults say they see the summaries often. Those overviews are built from passages.
For a plumber in Kettering or a conveyancing firm in Milton Keynes, the practical question is whether the passage that answers "how much does a boiler swap cost" or "how long does conveyancing take" exists on the site at all, in a form the model can lift on its own.
What Google means when it says you do not need to chunk content
Google says there is no need to break content into tiny pieces, and that is a warning about fragmentation, not a licence to write paragraphs that only work in context. The guide says "there's no requirement to break your content into tiny pieces for AI to better understand it", and its closing list says you "can ignore tactics like 'chunking' content".
Read the whole passage and the target is clear. Google is objecting to splitting one topic into dozens of thin pages or 40-word fragments to game retrieval. In the same breath it says its systems "understand the nuance of multiple topics on a page and show the relevant piece to users", and the relevant piece is a passage.
The same guide says what it does want: pages "organized by paragraphs and sections", with headings. Its companion page on AI features adds that important content should be "available in textual form". Chunking changes the shape of the site. Extractability changes the shape of each paragraph. Google warns against the first and describes the second as good writing.
Whole-page optimisation and passage-level extractability compared
The two approaches ask different questions of the same page, and the differences show up in how the page is written.
| Whole-page optimisation | Passage-level extractability | |
|---|---|---|
| Unit judged | The URL | Each heading plus the paragraphs under it |
| Where the answer sits | Anywhere on the page | First sentence under the heading |
| What "the firm" refers to | Set once in the intro | Named in the passage itself |
| Figures | Often on a separate pricing page | In the passage, with the source or date next to it |
| Headings | Keyword labels ("Our services") | The question the reader asked |
| Test | Does the page rank? | Does this paragraph make sense on its own? |
The right-hand column has research behind it. The 2023 GEO paper from Princeton and Georgia Tech researchers found visibility gains of up to 40% from methods that all make a passage easier to lift: adding quotations, statistics and cited sources. The authors also found the effect varied by subject area, so the 40% is a ceiling, not a promise. The later survey of 45 generative engine optimisation studies rates that 40% as a fixed-context result, not a promise of discovery.
The four things an extractable passage contains
An extractable passage has a heading that is the question, a first sentence that answers it, a body that names its own subject, and a figure with its source attached. Miss one and the passage can still be retrieved. Miss two and the model will usually find a cleaner passage on a competitor's page.
Fan-out queries are phrased as questions or near-questions, so a heading that reads "How long does a boiler installation take?" matches the sub-query directly. "Installation" does not.
The model scans for the sentence that answers, and it will take the first one that does. If your first sentence is "Every home is different", you have given it nothing.
Pronouns die at the passage boundary. "We offer this across the county" tells a model nothing about who "we" are or which county. Name the firm and the place in the passage, even if that feels repetitive on the page. Mostafa ElBermawy of NoGood makes the same point: entities should be named explicitly and consistently.
A number is the most quotable thing on a page, and a number with a date and a source beside it is also the most trustworthy, which is what a model weighing two candidate passages wants. "From £2,100" is weaker than "From £2,100 including VAT, our fixed price for a like-for-like combi swap, reviewed October 2026".
A UK service page paragraph, before and after
Here is a paragraph of the type we see on heating, law firm and accountancy sites across the Midlands. The firm, the prices and the times are invented for the example.
Before, under a heading that reads "Boiler installation":
At Hargreaves Heating we pride ourselves on delivering a professional and reliable boiler installation service across the region. Our highly experienced team of Gas Safe engineers are committed to providing the highest standards of workmanship and customer care, and we work with all leading manufacturers to find the right solution for your home. Contact us today for a free, no-obligation quote.
Run that through the four tests. The heading is a label. The first sentence answers nothing. The passage never says where "the region" is, and there is no figure. A model asked "how long does a new boiler take to fit in Northampton" has no sentence it can lift, and a reader has 61 words of claims they cannot check.
After, under the heading "How long does a boiler installation take?":
A like-for-like combi boiler replacement by Hargreaves Heating in Northampton takes one working day. Moving the boiler to a different room, or converting from a system boiler to a combi, usually takes two days because new pipework and a condensate route are needed. Our fixed price for a like-for-like swap is from £2,100 including VAT (reviewed October 2026). All installations are carried out by Gas Safe registered engineers and registered with Gas Safe within 30 days.
The length is similar. The heading is the question a homeowner types. The first sentence answers it, names the firm and the town, and gives a time. The second handles the obvious follow-up, the price carries a review date, and the Gas Safe claim can be checked. A model can lift the first sentence alone and it still makes sense.
The cost of this rewrite is that the firm had to commit to numbers. "One working day" and "from £2,100" are promises a reader can hold them to, which is what makes the passage worth quoting.
Google's May 2026 guide calls the opposite "commodity content", material that "could originate from anyone". The before paragraph could sit on any heating site in England. The after paragraph could only have come from this one.
A seven-point passage checklist
Apply these seven checks to every heading-plus-paragraphs block on a service page, one block at a time. We run this before any schema or technical work on an answer engine optimisation engagement, because schema cannot fix a passage that says nothing.
- The heading is the question a customer would actually type, in their words, in sentence case. "How much does a will cost?" not "Wills and probate".
- The first sentence under the heading answers the question directly. Context, exceptions and caveats come after it, never before.
- The passage names the firm and the place at least once in full. No "we", "our team" or "the region" doing the work of a proper noun.
- Every figure has a unit, a date or a source beside it. Prices say whether VAT is included. Times say working days or calendar days.
- The passage is readable on its own. Copy it into a blank document with its heading. If it needs the paragraph above it to make sense, rewrite the opening.
- The passage says one thing. Two questions under one heading means two headings. Google's objection to chunking is about thin pages, not about one topic per section.
- The passage contains at least one claim a competitor could not copy: a named process, a real limit, a decision the firm has made, a number from its own records.
The seventh point is where most pages fail. A passage that passes the first six and fails the seventh is well formatted commodity content, easy to extract and easy to replace.
Where to start on an existing site
Start with the three or four questions customers ask by phone or email before they buy, and check whether each one has a passage on the site that passes the checklist. On most UK service sites the questions are answered in person, and the page talks about the firm instead.
Those questions are the fan-out queries. One extractable passage for each costs less than a new page and does more. The passages can sit on the existing service page, each under its own question heading, which also sorts out much of the on-page SEO the page was missing.
Then look at the paragraph that opens each service page. It is almost always "about us" text wearing a service heading. Move the answer up, push the biography down, and name the town.
The decision rule we use: if a sentence would make no sense to a stranger who saw only that sentence and the heading above it, it is not an answer, and the engine will not treat it as one.
If you want a passage-by-passage review of your service pages against this checklist, our answer engine optimisation team can do that, or you can get in touch with the three questions your customers ask most and we will tell you whether your site answers them.