Card Sorting - Unlocking User Insights

By Philip Burgess – UX Research Leader

When designing intuitive and user-friendly digital experiences, understanding how users mentally organize information is essential. One of the most effective methods for uncovering this is Card Sorting—a deceptively simple yet powerful UX research technique.

What Is Card Sorting?

Card sorting is a method used to understand how users categorize and label information. Participants are given a set of “cards,” each representing a piece of content or functionality (e.g., “Shipping Info,” “Returns Policy,” “Product Reviews”), and asked to group them in a way that makes sense to them.

This helps UX designers and information architects:

• Discover natural groupings and hierarchies

• Validate or refine navigation structures

• Identify confusing or ambiguous labels

Types of Card Sorting

Card sorting comes in several flavors, each suited to different research goals and constraints. Here’s a breakdown:

Type	Description	Pros	Cons
Open Sort	Participants create their own categories and name them	Reveals users’ mental models and natural groupings	Can be messy and harder to analyze
Closed Sort	Participants sort cards into predefined categories	Useful for validating existing structures	Limits discovery of new groupings
Hybrid Sort	Combines open and closed—some categories are predefined, others are user-created	Balances structure with flexibility	Can be complex to interpret
Remote Sort	Conducted online using tools like OptimalSort or UXtweak	Scalable and convenient	Less contextual insight than in-person sessions
In-Person Sort	Physical cards are sorted in a moderated session	Rich qualitative feedback and observation	Time-consuming and less scalable

Tools for Card Sorting

If you're conducting remote card sorts, here are some popular tools:

• OptimalSort

• UXtweak

• UserZoom

• UsabilityHub

Best Practices

To get the most out of your card sorting study:

• Use clear, jargon-free labels on cards

• Limit the number of cards (20–30 is ideal)

• Pilot test with a few users before launching

• Combine with other methods like tree testing for deeper insights

When to Use Card Sorting

Card sorting is especially valuable during:

• Early stages of IA and navigation design

• Redesigns of complex websites or apps

• Validating assumptions about user behavior

Card sorting is more than just a pile of cards—it’s a window into how users think. By tapping into their mental models, you can craft experiences that feel intuitive, logical, and satisfying.