Card Sorting

Card sorting is a simple technique in user experience design where a group of subject experts or "users", however inexperienced with design, are guided to generate a category tree or folksonomy. It is a useful approach for designing information architecture, workflows, menu structure, or web site navigation paths.

Card sorting has a characteristically low-tech approach. The concepts are first identified and written onto simple index cards or Post-it notes. The user group then arranges these to represent the groups or structures they are familiar with.

Groups may either be organised as collaborative groups (focus groups) or as repeated individual sorts. The literature discusses appropriate numbers of users needed to produce trustworthy results.

A card sort is commonly undertaken when designing a navigation structure for an environment that offers an interesting variety of content and functionality, such as a web site. In that context, the items to be organized are those that are significant in the environment. The way that the items are organized should make sense to the target audience and cannot be determined from first principles.

The field of information architecture is founded upon the study of the structure of information. If an accepted and standardized taxonomy exists for a subject, it would be natural to simply apply that taxonomy as a means of organizing both the information in the environment and any navigation to particular subjects or functions. Card sorting is applied when:

• The variety in the items to be organized is so great that no existing taxonomy is accepted as organizing the items.
• The similarities among the items make them difficult to divide clearly into categories.
• Members of the audience that uses the environment may differ significantly in how they view the similarities among items and the appropriate groupings of items.