My UX toolkit: Card sorting and tree testing
My UX Toolkit is a series of posts exploring different tools and techniques used in the user experience design and research process, my understanding of them, and when they can be applied. UX is a broad and varied space that can range from quantitative statistical analysis to graphic design, from branding and content strategy to storyboarding. Here I am trying to scratch the surface of how UXers UX, share my knowledge and further my own understanding of this vast career field.
In the field of UX design, both card sorting and tree testing are research methods that help designers to sort and categorize the content that will be contained within a website or app. Card sorting is a great place to start when determining the information architecture of a design, and tree testing is a good way to validate or iterate on assumptions about how users will categorize and group content. Both methods gather information directly from the foremost experts on categorizing a product’s content, the users.
Card Sort
Traditionally a card sort consisted of writing concepts, topics or products down on index cards, and recruiting participants to sort the cards into categories that made sense to them. Ideally you would have 15 participants, and no more than 40 cards. These days most card sorts are conducted virtually via software like Optimal Workshop. This saves time and money.
Closed
In a closed card sort, participants group cards based on predetermined labels. This gives the participants less freedom and flexibility to categorize things in a way that makes sense to them, but it is more likely to reveal patterns and trends in all the information gathered.
Open
An open card sort allows for participants to group cards into labels of their own creation, or without labels at all. This method is less likely to reveal trends or consistent patterns among the different participants, but it can reveal insights into individual users’ thought processes. This method is best used in the more exploratory phase of a project.
Hybrid
To get the best of both worlds, you can conduct a hybrid card sort. This means providing some categories for participants to sort cards into, but allowing them to also create and label their own categories if they feel a specific card doesn’t fit those given.
Tree Testing
In my mind, tree testing is like the inverse of card sorting. Starting with an existing website, a tree test can validate the information architecture or illuminate where the user is getting lost when looking for specific information.
For this test, done virtually, you take the hierarchy of the information contained on a website and create something similar to a site map. Then participants are given a scenario and test the information architecture of the site by trying to locate specific information. Based on the results of the test you can determine whether your labels and categories make sense to users, and iterate on the system as needed.
