Card Sorting

By Philip Burgess | UX Research Leader

Card sorting is a simple yet powerful technique used to organize information in a way that makes sense to users. It helps designers, developers, and researchers understand how people group and label content, which improves website navigation, app menus, and overall user experience. This post explores what card sorting is, how it works, and practical ways to use it effectively.

Cards sorted into categories on a wooden table

What Is Card Sorting?

Card sorting is a user research method where participants organize topics or items into categories that make sense to them. Each item is written on a card, either physical or digital, and participants group these cards based on their understanding. They may also label the groups with names they find appropriate.

This method reveals how users think about information and helps create intuitive structures. It is especially useful when designing websites, apps, or any system that requires clear navigation and content organization.

Types of Card Sorting

There are three main types of card sorting:

• Open Card Sorting

Participants create their own categories and names. This approach uncovers natural groupings and terminology users prefer.

• Closed Card Sorting

Participants sort cards into predefined categories. This method tests if the existing structure works well for users.

• Hybrid Card Sorting

Combines open and closed methods. Participants sort cards into given categories but can also create new ones if needed.

Each type serves different goals. Open sorting is best for early design stages, while closed sorting helps validate existing structures.

How to Conduct a Card Sorting Session

Running a card sorting session involves a few clear steps:

1. Prepare the Cards

   List all items or topics you want to organize. Write each on a separate card. Keep the list manageable, usually between 30 and 60 cards.

   
   

2. Choose Participants

   Select people who represent your target audience. Aim for at least 15 participants to get reliable results.

   
   

3. Explain the Task

   Tell participants to group cards in a way that makes sense to them. For open sorting, ask them to name each group.

   
   

4. Observe and Record

   Watch how participants sort cards and take notes. If digital tools are used, data is collected automatically.

   
   

5. Analyze Results

   Look for patterns in how cards are grouped and named. Identify common categories and any confusing items.

   
   

Tools for Card Sorting

Card sorting can be done with physical cards or online tools. Physical cards work well for small groups or in-person sessions. Online tools offer convenience and automatic data collection, especially for remote participants.

Popular online card sorting tools include:

• OptimalSort

• UserZoom

• UsabilityHub

  
  

These platforms allow easy setup, participant invitations, and detailed analysis reports.

Benefits of Card Sorting

Card sorting offers several advantages:

• Improves Navigation

Helps create menus and categories that users find logical.

• Enhances User Experience

Reduces confusion by aligning content structure with user expectations.

• Saves Time and Money

Identifies problems early before development or redesign.

• Supports Content Strategy

Guides how content is grouped and labeled across platforms.

Practical Example of Card Sorting

Imagine a team designing an online bookstore. They want to organize book categories so customers find what they want quickly.

• They prepare cards with book genres like "Science Fiction," "Romance," "History," and "Children’s Books."

• Using open card sorting, participants group these cards and create labels such as "Fiction," "Non-Fiction," and "Kids."

• The team notices most users group "Science Fiction" and "Romance" under "Fiction," while "History" falls under "Non-Fiction."

• Based on this, the bookstore’s menu is structured with clear, user-friendly categories.

  
  

This approach ensures the website matches how customers think about books, making browsing easier.

Hands sorting cards into labeled groups during a card sorting exercise

Tips for Effective Card Sorting

To get the most from card sorting, consider these tips:

• Keep the number of cards manageable to avoid participant fatigue.

• Use clear, simple language on cards.

• Include a mix of familiar and new items to test understanding.

• Encourage participants to think aloud during the process.

• Combine card sorting with other research methods like interviews or usability tests.

• Analyze results carefully, looking for consensus and outliers.

  
  

When to Use Card Sorting

Card sorting works best when:

• Designing or redesigning website navigation.

• Creating menus for apps or software.

• Organizing large amounts of content.

• Developing taxonomies or classification systems.

• Testing existing information structures.

  
  

It is less useful for very small projects with limited content or when the structure is already well established.

Summary

Card sorting is a straightforward way to understand how users organize information. It helps create clear, user-friendly navigation and content structures. By involving real users in grouping and labeling content, teams can build products that feel natural and easy to use.