Lenny’s Newsletter · Subscriber post · Building AI products · Discovery & customer research

How to do AI analysis you can actually trust

Four prompting techniques to prevent AI’s most common mistakes

Lenny RachitskyFeb 17, 202626 min♥ 421
SourceLenny’s Newsletter
KindSubscriber post
PublishedFeb 17, 2026
Readers♥ 421
Originallennysnewsletter.com ↗
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Caitlin Sullivan, a user-research practitioner, explains four recurring ways AI-generated customer analysis goes wrong: invented or blended quotes, generic insights, signal that doesn't guide decisions, and missed contradictions. She pairs each failure mode with a prompting fix such as quote rules, context loading, few-shot calibration, and a final verification pass. The core argument is that AI output looks confident, so verification must be built into the workflow.

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01Key takeaways

  • AI analysis of interviews and surveys often invents or blends quotes, so define quote rules and verify each one.
  • Generic themes come from models defaulting to consensus; provide project, business, product, and participant context.
  • Teach your scoring scale with concrete labeled examples and the reasoning behind each label, not just descriptions.
  • Run a dedicated verification pass to catch fabricated evidence, contradictions, and weakly supported findings before presenting.
  • Different LLMs have different strengths for analysis, so test across models and know each one's tendencies.
“These mistakes are invisible until a stakeholder asks a question you can’t answer, or a decision falls apart three months later.”Caitlin Sullivan · Lenny’s Newsletter
“Verification is the difference between AI output you’ll always second-guess and insights you can stand behind.”Caitlin Sullivan · Lenny’s Newsletter

02Frameworks mentioned

Summary and takeaways written by PM Atlas; quotes are short excerpts. © the original author.