The accuracy question
The first question anyone asks about synthetic buyer interviews is: how accurate is this?
It is the wrong question. Not because accuracy does not matter, but because a single accuracy number misrepresents what the tool does.
BuyerLens, the buyer-interview layer of pre-spend creative intelligence, does not predict what a specific real person would say. It simulates plausible reactions grounded in personality traits, category context, and RoastIQ evidence. The output is a directional signal, a pressure test rather than a measurement.
What we show instead of accuracy
BuyerLens surfaces three indicators of study strength.
1. Theme convergence
When multiple personas independently flag the same objection, the signal is stronger. If 3 out of 3 buyers say the value proposition arrives too late, that convergence suggests a structural issue rather than a random output.
When personas disagree, that disagreement is also informative. It tells you the objection is segment-specific, not universal.
2. Context specificity
Every BuyerLens study opens from a RoastIQ result; one that carries that evidence into its audience and goal is stronger than one left on generic defaults. A study with uploaded source documents (briefs, reviews, past research) is stronger still.
We show what context was available. Was the RoastIQ evidence carried through? Were source documents attached? Was the audience description specific or generic?
3. Coverage breadth
With 3 personas, you get directional objections. With 8 to 10, you cover more of the buyer landscape. With 15, you approach saturation, the point where additional interviews produce diminishing new themes.
We do not set a minimum. We make the coverage visible so you can judge whether the study is strong enough for the decision at hand.
When a study is strong enough to act on
A BuyerLens study is strong enough to act on when:
- Multiple personas converge on the same objection. Not just one voice, but a pattern
- The objection maps to a specific RoastIQ KPI. It explains a score, rather than just expressing a feeling
- The fix direction is specific enough to brief. Not "fix the ad" but "move the product demo to seconds 3 to 5"
- The context was specific. RoastIQ evidence, a real audience description, and ideally source documents
A study is not strong enough when:
- Only one persona raises the objection and the others disagree
- The objection is generic ("this ad is not engaging enough") rather than specific
- The RoastIQ evidence was dropped in favor of generic defaults
- The audience description was too broad to produce meaningful segmentation
The honest position
BuyerLens is a pressure test. It gives you a directional signal about buyer resistance before you commit to an edit direction. It is not a consumer panel, not a focus group, and not a prediction of market response.
It also does not reproduce survey methodology. Traditional creative testing asks real people to recall and report. BuyerLens runs structured synthetic buyer interviews: personality-weighted personas from a directory of 36 react to your specific creative evidence. Those are different constructs, and a study that converges strongly is still simulation rather than measurement.
The anchoring RoastIQ scores are validated model predictions (held-out Spearman ρ +0.30 to +0.32 on public engagement and click-intent outcomes, May 2026, not ROAS or sales; see the methodology). BuyerLens output carries no equivalent validation, hence coverage indicators instead of an accuracy number.
The right way to use it: as one input alongside the RoastIQ diagnostic, the team discussion, and the creative judgment. Its outputs are directional hypotheses to verify, not evidence about real consumers, never the final word.
For the method behind synthetic research generally, including where it fails, see synthetic users for marketing research.