What is card sorting in UX research?
Card sorting is a UX research method in which participants are given a set of cards, each representing a piece of content, a feature, or a concept, and asked to organize them into groups that feel logical and natural to them. The groups participants create and the labels they choose for those groups reveal their mental-model of the content and inform decisions about information architecture, navigation structure, and labeling.
What are the types of card sorting?
Open card sorting asks participants to create their own groups and give them their own labels. There are no predefined categories. This approach is used to discover how users naturally think about and organize content, making it most valuable in the early stages of designing an information architecture.
Closed card sorting gives participants a set of predefined categories and asks them to sort cards into those categories. This approach is used to validate an existing structure or test whether proposed navigation labels are intuitive to users.
Hybrid card sorting combines both approaches. Participants can use predefined categories or create new ones if none of the existing options feel right. It provides both validation of the existing structure and discovery of gaps or alternatives.
Why is card sorting important in UX design?
Navigation labels and content categories that feel obvious to the team often make no sense to users. Card sorting removes the assumption that the team's mental model matches the user's. It is one of the most efficient research methods available: a session with fifteen to twenty participants generates enough data to restructure an entire navigation system with confidence, at a fraction of the cost of discovering the same problems through post-launch analytics.
When should you use card sorting in UX?
Use open card sorting when designing a new navigation structure or when current navigation is known to be problematic but the cause is unclear. Use closed card sorting when you have a proposed structure and want to validate whether users can find items within it. Use hybrid card sorting when you want to test a proposed structure while leaving room to discover what users expect that your structure doesn't provide.