Confirmation Bias
Also known as: Motivated Reasoning, Hypothesis Bias
The tendency to weight evidence that confirms prior beliefs and discount evidence that challenges them.
Full Definition
Confirmation bias is one of the most damaging forces in the analysis phase of discovery research. By the time interviews are complete, teams have emotional investment in their hypothesis. Findings that confirm the hypothesis feel more important than they are. Findings that challenge it are minimized or explained away. Confirmation bias is countered by tagging before analyzing, actively counting disconfirming evidence, reporting frequencies precisely, and involving a skeptical reviewer.
Example
A team hears eight interviewees say the problem is manageable and two say it is acute. They build their pitch around the two because those findings confirmed their hypothesis. The two are real. They are just not the market.