What can go wrong in a survey?

Plenty. Questions can be unclear, biased, repetitive, or just off-topic. Respondents might not understand the wording, or get forced into an answer that doesn't really fit their situation. You might be sending it to the wrong audience, or your sample might be too small to draw real conclusions from. Bad timing can mean people answer before they've had enough experience to give a useful opinion.

A survey that runs too long causes fatigue, drop-off, or careless answers near the end. Some people will hit technical problems on certain devices and just give up. And on the analysis side, teams sometimes read correlation as causation, or only pay attention to the answers they like. Careful planning, testing beforehand, and honest analysis cut down on most of this.