Quality of Evidence - All Things Product Podcast with Teresa Torres & Petra Wille
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You've got behavioral analytics, support tickets, sales call notes, and a feedback inbox that never empties. With all that data coming in, do product teams actually still need to go out and talk to users?
In this episode, Petra Wille and Teresa Torres dig into why not all product evidence is created equal — and why the type of data you collect matters just as much as the volume. Teresa introduces her "ladder of evidence" framework and shares what she's learning from real interview transcripts through her work at Vistaly: that many teams are confusing product demos, stakeholder meetings, and opinion-gathering sessions for genuine customer research.
They explore the spectrum from low-quality signals (support tickets, app store reviews) to rich, story-based interviews — and why the goal isn't perfection, but moving in the right direction. Plus: why even a mediocre interview is better than no interview at all, and how to coach teams toward stronger evidence without discouraging them from talking to customers in the first place.
What We Cover in This Episode
- Why product teams are drowning in data — but still making uninformed decisions
- The danger of projecting your own expertise onto low-quality signals
- Teresa's "ladder of evidence" framework: as effort goes up, so does value
- Henrik Kniberg's triangle (Petra's coaching go-to): quantitative data + organizational signal + qualitative insight
- What Teresa is learning from real interview transcripts at Vistaly — and why many "interviews" aren't really interviews
- The spectrum of interview quality: story-based interviews vs. direct-question interviews vs. usability preference gathering
- Why product demos and stakeholder meetings are being mistaken for customer research
- How to communicate signal strength without discouraging teams from interviewing
- The strategic product decision behind Vistaly's choice to support imperfect interview formats — and use them as coaching moments
- Why vibe-coded software makes good interviewing skills more critical than ever
Key Concepts & Frameworks
- Ladder of Evidence — Teresa's framework for thinking about evidence quality. Low-effort signals (support tickets, app store reviews, sales call notes) are abundant but carry weak signal strength. High-effort, story-based interviews are harder to collect but carry far more context for decision-making.
- Story-Based Interviewing — Rather than asking customers about preferences or opinions, story-based interviews collect the narrative of a specific experience: what were you trying to do, when did this come up, what went wrong, what did you need? This context is what makes evidence actionable.
- Signal vs. Insight — Low-quality signals tell you something is worth exploring. They rarely tell you what to build. The risk: product experts fill in the gaps with their own assumptions and get it wrong.
Quotes Worth Saving
"We're inundated with these low-value signals all the time, but they rarely carry enough signal strength to actually tell us what we should be building. But they feel like they do." — Teresa Torres
"The worst thing you could do is never talk to a customer. The best thing you can do is collect a really rich story about their experience." — Teresa Torres
"It is easier than ever to release mediocre software. People need to get better at interviewing." — Petra Wille
Resources & Links:
- Follow Teresa Torres: https://ProductTalk.org
- Follow Petra Wille: https://Petra-Wille.com
Mentioned in this episode:
- Teresa’s blog:
Ask Teresa: What Should You Do With Insights That Don’t Come from Customer Interviews?
Story-Based Customer Interviews Unlock Missing Context
The Ladder of Evidence: Get More Value From Your Customer Interviews and Product Experiments - Learn more about story-based customer interviews in Teresa’s course: Story-Based Customer Interviews
- Henrik Kniberg's Triangle — a framework Petra uses in coaching to ensure teams triangulate quantitative data, organizational signal, and qualitative evidence before acting
Minimise the Gap Between Maker and User by Henrik Kniberg - Vistaly — Teresa's partnership for AI-generated interview snapshots and opportunity solution trees
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