Card Sorting

Card sorting is a simple technique for discovering how users group objects, concepts or any type of category.

In UX web design it is most often used to help design the information architecture of a website, once the basic content of site is known.

The aim is to create an information architecture that reflects how your users see, or would like to see, your information. This is likely to be very different to how your business or organisation sees it information.

How to do a card sort

In its most basic implementation users are asked to group together content categories printed out on individual cards. Users can group the cards into as many groups as they want, and the groups can be of any size the user decides.

Users will group together what they view as being thematically linked items. For example users a common grouping would be:

Frequently asked questions (FAQS)
Site help

(FAQS and site help being both 'help' type content classes).

The card sorting exercise can be made progressively more sophisticated by, for example by:

Asking the users to create title for the logical groups they create
Allowing users to locate items in more than one group
Ask users to comment on whether the content categories are clear/self explanatory

Each individual user's card sort is recorded, and although card sorting can be done in groups human computer interaction is usually done as a solitary activity, so testing user subjects separately provides a better analogue.

Card sorting requires more test subjects that usability testing. The industry standard is to use a minimum of 15 test users, and a maximum of 30.

The results of all test subjects are compared and correlation scores are compiled. So for example if all users groups 'FAQS' and 'Site help' together the correlation score would be 100%.

Output of card sorting

Users comments and suggestions for group names and title, including alternative title and terms can be used in naming Information Architecture components such as page title, heading titles and link phrases, and can also be a valuable source material for the creation of metadata, body copy, and in the implementation of search engine optimisation techniques.