What is Grounding?

At a glance

• Grounding constrains a model to what the retrieved documents say, not what it remembers.
• A citation is evidence of grounding only if the cited page supports the sentence beside it.
• Grounding is a matter of degree: parts of one answer can be grounded while others are not.
• Pages stating facts plainly, with dates and sources, are easier to ground against and get used more.

Tying a claim to a document

The system retrieves passages, puts them in front of the model, and instructs it to answer from those passages rather than from memory. Google Cloud’s grounding overview describes this as connecting the model to a verifiable source of information, and the original RAG paper set out the architecture that made it practical.

Then it checks, or tries to. Some systems run a verification pass mapping each sentence back to a supporting passage and flagging anything unsupported. Others rely on the instruction alone.

Gaps are where it breaks. If the retrieved passages cover most of what a question needs, the model still writes a complete answer. The missing part comes from training data, arrives in the same confident tone, and often sits beside a citation belonging to the sentence next to it.

Groundedness decides who gets named

Every brand asks how to get cited. The more useful question is which of your claims a machine could defend if challenged.

A generative system prefers passages it can point at without risk. “Our jackets are highly breathable” grounds nothing, because it supports no specific claim. A sentence giving the membrane rating, the test standard and the date grounds cleanly, and the system reaches for it.

That is why thin, confident marketing copy underperforms in retrieval-augmented generation even when it ranks well. The page is retrievable but not usable, while a plain spec table nobody visits gets quoted week after week.

The logic runs in reverse too. When nothing groundable exists about your brand, the model fills the gap from memory, which is where a hallucination about your products comes from.

Make your pages easy to ground against

Groundability is a property of sentences. You can improve it this week.

1. Turn adjectives into measurements. “Long battery life” grounds nothing. “Rated for a full working day of continuous use, with the test date printed beside it” grounds a claim.
2. Attach a source to every figure you publish, including your own. Say who counted, when, and over what sample. Unattributed numbers get skipped.
3. Give every product a facts block in plain HTML: materials, dimensions, compatibility, warranty. Boring, structured and quotable beats persuasive prose.
4. Fix contradictions between your own pages. When two of your pages disagree, a careful system uses neither and a careless one picks at random.
5. Date your claims visibly. A groundable fact with no date decays into an ungroundable one.