Mastering Card Sorting in UX Research for Deeper User Understanding

By Philip Burgess | UX Research Leader

Understanding how users organize information is key to creating intuitive digital experiences. Card sorting is a simple yet powerful UX research method that reveals how users think about content and structure. By mastering card sorting, designers and researchers can build websites, apps, and products that feel natural and easy to navigate.

This post explains what card sorting is, how to run effective sessions, and how to analyze results to unlock valuable user insights.

Card sorting session showing grouped cards on a table

What Is Card Sorting and Why It Matters

Card sorting involves giving users a set of cards, each representing a piece of content or feature, and asking them to group these cards in a way that makes sense to them. This method helps uncover users’ mental models—the way they categorize and relate information.

When designers understand these mental models, they can create navigation menus, site maps, and content structures that match user expectations. This reduces confusion, improves findability, and enhances overall user satisfaction.

Card sorting is especially useful when:

• Designing new websites or apps with complex content

• Restructuring existing information architecture

• Validating assumptions about how users organize information

  
  

Types of Card Sorting

There are three main types of card sorting, each suited to different research goals:

• Open Card Sorting

Users create their own groups and label them. This reveals natural categories and terminology users prefer.

• Closed Card Sorting

Users sort cards into predefined groups. This tests how well existing categories work.

• Hybrid Card Sorting

Users sort cards into predefined groups but can also create new groups if needed. This combines exploration and validation.

Choosing the right type depends on whether you want to explore user thinking or validate a proposed structure.

Preparing for a Card Sorting Session

Preparation is key to getting useful results. Follow these steps:

• Select the content

Choose 30 to 60 cards representing key content or features. Too many cards overwhelm participants; too few limit insights.

• Write clear card labels

Use simple, concise terms that users will understand. Avoid jargon or ambiguous words.

• Decide on sorting method

Choose between physical cards or digital tools. Digital tools like OptimalSort or UXtweak allow remote sessions and automatic data collection.

• Recruit participants

Aim for 15 to 30 users who represent your target audience. More participants increase reliability.

• Prepare instructions

Explain the task clearly. For open sorting, ask users to group cards in a way that makes sense and name each group.

Running the Card Sorting Session

During the session:

• Observe without influencing

Let users sort cards naturally. Avoid suggesting groupings or labels.

• Encourage thinking aloud

Ask users to explain their reasoning. This adds qualitative insights.

• Take notes or record sessions

Capture observations about confusion, hesitation, or interesting patterns.

• Keep sessions short

Aim for 30 to 60 minutes to maintain focus.

Analyzing Card Sorting Results

Once sessions are complete, analyze the data to identify patterns:

• Group similarity

Look for cards frequently grouped together across participants. These indicate strong associations.

• Category labels

Review user-generated group names to find common terms or themes.

• Outliers

Identify cards that users sorted inconsistently. These may need clearer labeling or reconsideration.

• Cluster analysis

Use software tools to create dendrograms or similarity matrices that visualize relationships between cards.

• Compare with existing structure

If you have a current navigation, see how well it aligns with user groupings.

Applying Insights to Design

Use card sorting findings to:

• Build navigation menus that reflect user categories

• Rename labels to match user language

• Simplify complex structures by merging or splitting groups

• Prioritize content placement based on user expectations

  
  

For example, a news website might discover users group articles by topic rather than date, prompting a redesign of the homepage layout.

Digital card sorting tool displaying grouped content cards with user-generated labels

Tips for Successful Card Sorting

• Test your card labels with a small group before the main sessions

• Use a mix of qualitative and quantitative analysis

• Combine card sorting with other UX methods like user interviews or tree testing

• Be open to unexpected groupings or labels

• Document findings clearly for the design team

  
  

Final Thoughts on Card Sorting in UX Research

Card sorting offers a direct window into how users organize information. It helps designers create structures that feel intuitive and reduce user frustration. By carefully planning, running, and analyzing card sorting sessions, you gain clear guidance for building user-centered navigation and content layouts.