Understanding card sorting and tree testing in UX research

Card sorting and tree testing are complementary UX research methods used to understand how users mentally categorise information and navigate hierarchical structures.

In the context of loyalty programs — where menus, categories, and reward structures can be complex — these methods help reveal whether information architecture aligns with users’ expectations and logic.

Card sorting explores how users group concepts, while tree testing evaluates whether a proposed structure supports accurate and efficient navigation.

Why these methods matter for loyalty UX

Loyalty experiences often involve layered information — such as reward categories, benefit tiers, point histories, and redemption options — that users must locate and understand quickly.
Mismatches between how information is organised and how users think can lead to confusion, misclicks, and disengagement.

Card sorting and tree testing help answer questions like:

• How do users categorise reward types and loyalty features?
• Does the current navigation reflect users’ mental models?
• Are important sections easily discoverable?
• Which labels or paths cause hesitation or error?

What card sorting examines

Card sorting involves presenting users with a set of concepts (such as reward types, menu items, or feature names) and asking them to group or label them according to their expectations.
This reveals:

• natural groupings that inform categorisation
• preferred labels or terminology
• differences in understanding between novice and experienced users

Card sorting can be:

• Open — where users define their own groups
• Closed — where users sort into predefined categories

Both approaches provide insight into how users think about the content and structure.open (user defines categories) and closed (user sorts into predefined groups) card sorts — moderated or remote, depending on your team’s needs.

What tree testing examines

Tree testing evaluates the effectiveness of a proposed information structure by asking users to find specific items or paths without the influence of design elements like navigation bars or visual styling.
It reveals:

• which paths lead to correct finds
• where users make incorrect assumptions
• stages where hesitation or backtracking occurs

Tree testing focuses purely on the structure and terminology, isolating navigation logic from styling and layout variables.

Combined insights from card sorting and tree testing

When used together, these methods help answer deeper structural questions:

• Do users’ mental categories align with the system’s hierarchy?
• Which labels are intuitive versus ambiguous?
• How many clicks or decisions are needed to reach key loyalty features?
• Where structural friction arises even when individual tasks are simple?

These insights guide design decisions rooted in cognitive logic rather than guesswork.

Card sorting & tree testing in broader UX research

Card sorting and tree testing complement other UX research methods, such as usability testing, journey mapping, and behavioural analysis.
While usability testing highlights task performance and journey mapping reveals sequences of use, card sorting and tree testing focus specifically on how users conceptualise and traverse information structures.

Together, these methods contribute to a fuller picture of loyalty UX — one that includes cognition, navigation logic, and behavioural context.