Affinity diagramming has long been used in business to organize large sets of ideas into clusters. In UX, the method is used to organize research findings or to sort design ideas in ideation workshops.
User interviews have become a popular technique for getting user feedback, mainly because they are fast and easy. Use them to learn about users’ perceptions of your design, not about its usability.
Interviews
User Interviews: How, When, and Why to Conduct Them — NN/g
