> ## Documentation Index
> Fetch the complete documentation index at: https://docs.peec.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Rewording a prompt rarely changes AI brand visibility until similarity drops

> Peec's study of 37,804 AI responses (2026) — brand mentions hold while prompt variants stay above ~0.50–0.60 cosine similarity; below that they drop ~50%, hitting middle-of-funnel hardest.

Rewording a prompt barely changes which brands AI engines mention — until the rephrasing drifts past a measurable semantic threshold. Peec analyzed 1,754 prompts and 37,804 AI responses across five engines and 18 subverticals ([published study](https://www.searchenginejournal.com/ai-prompt-intent-keywords-peec-spa/576201/), 2026; methodology in the [SSRN working paper](https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6914539), Jun 2026), using two designs: 288 human-written prompts, and controlled variants stepped in tiny cosine-similarity intervals.

* **Human phrasing only looks chaotic.** \~88–92% of human prompt pairs for the same commercial need sit above 0.50 cosine similarity; \~95% above 0.40. Less than 10% of variations drift semantically far.
* **Mentions hold above the threshold.** As long as variants stay above \~0.50–0.60 similarity (engine-dependent), brand mentions stay stable. In the lowest bin (0.35–0.39), mention probability drops 2.40 percentage points against a 4.9% baseline — roughly a 50% relative decrease.
* **Middle-of-funnel is the sensitive zone.** Unbranded commercial discovery prompts ("best CRMs for a small remote team") drop off as early as the 0.60–0.65 bucket; top-of-funnel and branded bottom-of-funnel prompts are stable. Suggested tracking split: \~25% TOFU, 50% MOFU, 25% BOFU.
* **Beware the semantic blindspot:** "car rental Munich" vs "car rental Frankfurt" are 95% similar but different intents — a changed qualifier (location, product, demographic, brand) is a new intent.
* **Engines differ:** Google AI Overviews shows the most persistent MOFU sensitivity; Gemini's effect fades fastest — report engines separately.

Takeaway (2026): prompt tracking works, but not as a one-prompt measurement system — track a portfolio across semantic neighborhoods, funnel stages, and engines. How prompt *style* shifts baselines: [Prompt style and brand mentions](/research/prompt-style-and-brand-visibility).

**Source:** [How prompt wording impacts AI brand visibility](https://www.searchenginejournal.com/ai-prompt-intent-keywords-peec-spa/576201/), Peec via Search Engine Journal, 2026.