Summary: User Research is best performed early on and instead of simply validating your requirements, can help shape them.
Clarification: By user research we will discuss Field Studies, not user testing (also referred to as user research). While we're on terminology, Field Studies are also referred to as Ethnography or Ethnographic Field Studies.
Knowing what to do with your user research opportunity is important. The field study is a critical component of UX Design. It is often left out of most people's mental model (conceptions) about UX Design. User experience has two faces: Usability (ease of use) and Desirability (needs and wants). User research can help surface patterns, triggers, motivations and new innovations.
Let's explore how, when and why to make the most of User Research through common misconceptions.
Common misconceptions about User Research