Open Card Sort

By Philip Burgess | UX Research Leader

Understanding how users organize information is key to creating intuitive websites and applications. One effective method to gather this insight is the open card sort. This technique helps designers and researchers uncover how people naturally group content, which can guide navigation, labeling, and overall structure.

Open card sorting invites participants to categorize items in a way that makes sense to them, without predefined groups. This approach reveals user mental models, highlighting patterns and preferences that might not be obvious otherwise.

Participant organizing cards in an open card sort session

What Is Open Card Sort?

Open card sort is a user research method where participants receive a set of cards, each labeled with a piece of content or feature. Instead of sorting cards into preset categories, participants create their own groups and name them. This freedom allows researchers to see how users think about the content and what labels they find meaningful.

This method contrasts with closed card sort, where categories are fixed and participants only assign cards to those groups. Open card sorting is especially useful early in the design process when the information architecture is still flexible.

Why Use Open Card Sort?

Open card sorting provides several benefits:

• Reveals natural groupings: Users create categories based on their understanding, which helps designers build structures that feel intuitive.

• Generates user-friendly labels: Participants name groups, offering real-world language that can improve navigation and reduce confusion.

• Identifies unexpected connections: Sometimes users group items in ways designers did not anticipate, uncovering new insights.

• Supports content organization: The results guide menu design, site maps, and content hierarchies.

  
  

For example, a website redesign team might use open card sorting to understand how visitors expect to find product categories or services. This insight can prevent navigation that feels confusing or forced.

How to Conduct an Open Card Sort

Running an open card sort involves several clear steps:

1. Prepare the cards

   Write down content items, features, or topics on individual cards. Keep the list manageable—usually between 30 and 60 cards.

   
   

2. Recruit participants

   Choose people who represent your target audience. Their input will reflect real user perspectives.

   
   

3. Explain the task

   Ask participants to group the cards in a way that makes sense to them and to name each group.

   
   

4. Observe and record

   Take notes or record sessions to capture how participants explain their groupings and labels.

   
   

5. Analyze results

   Look for common groupings and labels. Use clustering techniques or software tools to identify patterns.

   
   

6. Apply findings

   Use the insights to design or improve your information architecture.

   
   

Tips for Effective Open Card Sorting

To get the most from an open card sort, consider these practical tips:

• Limit the number of cards to avoid overwhelming participants.

• Use clear, concise labels on cards to prevent confusion.

• Encourage participants to think aloud as they sort, revealing their reasoning.

• Avoid leading participants by not suggesting categories or labels.

• Combine with other methods like interviews or usability testing for deeper insights.

  
  

Tools and Software for Open Card Sorting

While open card sorting can be done with physical cards, many digital tools simplify the process, especially for remote participants. Some popular options include:

• OptimalSort: Offers both open and closed card sorting with easy analysis.

• UserZoom: Provides card sorting as part of a broader user research platform.

• Miro or MURAL: Collaborative whiteboards that can be adapted for card sorting exercises.

  
  

Using digital tools can speed up data collection and analysis, especially with larger participant groups.

Digital card sorting interface showing user-created groups

Examples of Open Card Sort in Practice

• E-commerce site: A retailer used open card sorting to understand how customers group products. Participants created categories like "Outdoor Gear," "Home Essentials," and "Fitness Equipment," which differed from the retailer’s original labels. The new categories improved navigation and boosted sales.

  
  

• Educational platform: Designers asked students to sort course topics. The students grouped courses by skill level and interest area, leading to a more personalized course catalog.

  
  

• Healthcare app: Patients sorted health features and information. Their groupings helped developers organize content by urgency and type, making the app easier to use.

  
  

When Not to Use Open Card Sort

Open card sorting is not always the best choice. Avoid it when:

• You have a clear, fixed set of categories and want to test if users assign items correctly (use closed card sort instead).

• The content set is too large or complex for participants to handle comfortably.

• You need quick validation rather than exploratory research.

  
  

Interpreting Open Card Sort Results

Analyzing open card sort data involves identifying patterns in how participants grouped and labeled cards. Look for:

• Common groups that appear across multiple participants.

• Popular labels that reflect user language.

• Outliers that suggest alternative ways to organize content.

  
  

Use this information to create a draft information architecture, then test it further with users.

Summary

Open card sort is a valuable method to understand how users organize information naturally. By letting participants create their own groups and labels, designers gain insight into user mental models that improve navigation and content structure. Whether you are designing a website, app, or product catalog, open card sorting can guide you toward clearer, user-friendly organization.