Every earlier study in this series changed the facts about a brand, or the context around it. This one changes neither. Same brand, same facts, same named competitors, same model. Only the way the buyer asks the question changes. We ran two separate tests: a 15-cell grid that varies the length and grammar of the question, and 7 writer-style personas, from a Google-style keyword typer to a formal older buyer. Both tests point to the same thing. A question that reads like a search-bar keyword loses to a full, natural sentence by the same 15.6 points, in both tests, on their own.
An earlier study, Brand Legibility, found that once a brand is named, it almost always gets mentioned. The real contest is winner rate: who gets presented as the top pick against named competitors. This study keeps every fact fixed and changes only the buyer's own question. We split the test into two separate layers, so a result in one layer can't be mistaken for a side effect of the other.
Here is the real text, not just summary numbers. Below is the full 15-cell length and sentence-type grid for one of the four brands we tested (Barbaro Mojo, Cuban-style hot sauce), plus one example prompt per persona. Every brand ran all 15 grid cells and all 56 persona prompts. What you see below is the exact wording used, word for word.
| Length level | Declarative | Imperative | Question |
|---|---|---|---|
| L1 · bare | "Hot sauce." | "Hot sauce." | "Hot sauce?" |
| L2 · qualified | "Need Cuban-style hot sauce." | "Find me Cuban-style hot sauce." | "Cuban-style hot sauce?" |
| L3 · "best X" phrase | "Want the best Cuban-style hot sauce." | "Recommend the best Cuban-style hot sauce." | "What's the best Cuban-style hot sauce?"Weakest cell |
| L4 · full question | "I need a good brand of Cuban-style hot sauce." | "Recommend a good brand of Cuban-style hot sauce." | "What's a good brand of Cuban-style hot sauce?"Ceiling, 100% |
| L5 · paragraph | "I'm looking for Cuban-style hot sauce. I grew up on real Cuban food and I'm tired of hot sauces that just taste like generic vinegar heat, so I want something that actually tastes like real mojo criollo, not a knockoff." | "Please recommend Cuban-style hot sauce. I grew up on real Cuban food and I'm tired of hot sauces that just taste like generic vinegar heat, so I want something that actually tastes like real mojo criollo, not a knockoff." | "What's a good option for Cuban-style hot sauce? I grew up on real Cuban food and I'm tired of hot sauces that just taste like generic vinegar heat, so I want something that actually tastes like real mojo criollo, not a knockoff." |
If length worked the way most prompting advice assumes, the shortest or the longest prompt would win. That is not what happened. A one-word query does fine. A full paragraph with context does fine too. The weakest cell in the whole grid is the short "best X" style phrase. This pattern held up across all three scoring methods we used, including the final, trusted LLM-judge pass (χ²=32.29, p=0.000002).
This finding is worth explaining honestly, because our first read of it was wrong. A simple scoring rule (checking if the brand's first mention fell in the first 15% of the response) first showed declarative statements beating questions by 21 points. When we read a sample of the real responses by hand, we found the bug. Many replies open with a lead-in sentence before a numbered list. So a brand that was genuinely "1." on that list still got marked a loser, because its first mention came after that lead-in sentence. A rule-based fix only matched the original method 85.4% of the time, and it flipped the finding's direction. We did not trust either version. So every response was sent to a real gpt-4o judge and asked one question: was this brand the top recommendation? The numbers below come from that judge.
We tested seven writer-style personas. Each one used 8 different template phrasings, so no result depends on a single sentence. All seven ran the same way across all four brands.
Where the persona writing styles come from. The styles used for the younger and older personas are not guesses. They are based on real, published research on how different age groups write online. Older writers tend to read a period at the end of a sentence as clear and professional. One survey found 71% of adults over 50 read it that way. Gen Z writers more often skip the period and use "!" for enthusiasm instead. Emoji use also skews younger: 68% of Gen Z uses emoji regularly, including at work, compared to 36% of adults over 50. Sources: Stockton University, Talk Business (2025), and Thurlow (2002), "Generation Txt?"
These prompts were written by us, following these known patterns. They are not a claim about how every person in any group writes. The finding below is about how the model responds to a writing style, not about verified demographic behavior.
Our first look at the data hinted at a real connection between persona and brand: one brand spiked for specific personas in a way that looked like a genuine style-brand match. Once every response went through the same LLM-judge correction described above, that pattern mostly went away. Under the trusted scoring, the persona-by-brand results are close to 100% almost everywhere, with two exceptions. One brand (body piercing jewelry) scores lower across most personas. Google-style phrasing scores lower across all four brands. A logistic regression that controls for brand confirms both the length effect and the persona effect hold up on their own (both p<0.01). The honest read is two separate weak spots that add up, not one strong style-and-brand interaction.
The most reassuring part of this page might be what did not show up. There is no consistent age or gender bias among the six human-styled personas, once the scoring was done properly. A formal older buyer and an informal Gen Z buyer, asking for the exact same thing, land in roughly the same place, both near the ceiling. What actually moved the result, in two separate tests that have nothing to do with each other, was the same pattern: a bare, keyword-style phrasing that reads like a search bar instead of a real question. If there is a practical takeaway here, it is about how people write to AI assistants, not about who they are. A full sentence beats a keyword string by roughly the same amount, no matter who is typing it.
The final gpt-4o judge agreed with the original method 90.1% of the time on the length grid and 90.5% on the personas. That is higher than the 85.4% agreement of our own rule-based re-score attempt. Even that in-between fix was not perfect. Only the real judge is treated as the trusted source on this page.
A logistic regression that controls for brand confirms both effects hold up on their own. The length effect stays significant (likelihood-ratio test, p<0.00000001), and so does the persona effect (p=0.003). Neither one is just a side effect of one brand's overall strength.
The sentence-type finding changed direction once, then changed size again, across three rounds of scoring on the same data. We showed all three rounds here, not just the final number. Candidacy (whether the brand gets mentioned at all) sits at 97 to 100% across nearly every cell and persona. That matches the rest of this series. The real signal in this study is entirely in winner rate, not candidacy. We used four brands, reused from Brand Legibility because their facts were already verified. That is a narrow category spread: organic baby clothes, body piercing jewelry, Cuban-style hot sauce, and ceramic dinnerware. The persona layer tests writing style, not stated identity. A prompt that directly states the asker's age or gender, like "As a 65-year-old man...", is a separate follow-up we have not run yet. This study used one model, one system-message setup, and one round of 704 calls.
If a keyword-style query can cost a brand 15.6 points against the exact same facts, it's worth knowing what a model already has to work with when someone asks about you, however they happen to phrase it.
This study looks only at the shape of the buyer's question. It sits alongside the series' other studies on what shapes candidacy and selection once a brand's facts are already fixed.
Illustrative example · single-site signal for atomfoundry.dev.
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