Confirmation bias

The tendency to notice evidence supporting what you already believe and discount evidence against it.

Example

Counting the three people who said 'sounds interesting' and forgetting the eleven who did not reply.

Important

This is the single biggest threat to customer discovery, because the person running the interviews desperately wants a particular answer.

Related terms

  • Customer interview — A structured conversation about what someone actually does today, designed to produce evidence rather than encouragement.
  • Willingness to pay — Evidence that someone will part with money, as distinct from saying they like the idea.

Lessons that explain it

  • Why customer discovery comes first — The cheapest way to find out you are wrong. Twenty conversations cost two weeks; building the wrong thing costs a year. (10 min)
  • How to run a problem interview — A specific script, the questions that work, and the ones that quietly destroy your data. (15 min)
  • Reading the evidence honestly — Separating what people said from what it means, and noticing when you are hearing what you hoped for. (12 min)

All 176 terms in the Founder glossary