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.
At the beginning of a UX research and design project a Stakeholder Interview should be conducted to find out the Business Goals, Existing Research including User Research, Competitors and Technological Limitations.
Interviews
Stakeholder Interview — UX Knowledge Base Sketches