Mastering Card Sorting Techniques and Best Practices for Effective User Research

By Philip Burgess | UX Research Leader

Understanding how users organize information is key to designing intuitive websites, apps, and products. Card sorting is a simple yet powerful method to uncover how people group content, helping designers create clear navigation and structure. This post explores different types of card sorting, practical tips, and best practices to get the most from this user research technique.

Person organizing cards during a card sorting exercise

What Is Card Sorting and Why Use It?

Card sorting involves participants organizing topics or items written on cards into groups that make sense to them. This method reveals how users think about content, which can differ from how designers or stakeholders expect. The insights help build navigation menus, categorize products, or structure content in a way that feels natural to the audience.

Using card sorting early in the design process reduces guesswork and improves usability. It also uncovers terminology users prefer, which can guide labeling and descriptions.

Types of Card Sorting

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

• Open Card Sorting

Participants create their own groups and name them. This method is useful when you want to explore how users naturally categorize information without any predefined structure.

• Closed Card Sorting

Participants sort cards into predefined categories. This approach tests whether existing categories make sense to users and helps refine or validate a current structure.

• Hybrid Card Sorting

Combines open and closed methods. Participants sort cards into existing categories but can also create new groups if needed. This provides flexibility and deeper insights.

Choosing the right type depends on your project stage and what you want to learn. For example, open sorting works well during discovery, while closed sorting fits validation phases.

Preparing for a Card Sorting Session

Good preparation ensures smooth sessions and reliable results. Here are key steps:

• Select the Content

Choose 30 to 60 cards representing the main topics or items users will encounter. Avoid too many cards to prevent fatigue.

• Write Clear Card Labels

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

• Decide on the Sorting Method

Pick open, closed, or hybrid based on your goals.

• Recruit the Right Participants

Aim for 15 to 30 users who match your target audience. More participants improve data reliability.

• Choose a Format

Card sorting can be done in person with physical cards or online using tools like OptimalSort or UserZoom. Online tools simplify data collection and analysis.

Running the Card Sorting Session

During the session, keep these points in mind:

• Explain the Task Clearly

Tell participants what to do and why their input matters. Encourage them to think aloud if possible.

• Avoid Leading Participants

Let users group cards naturally without suggesting categories or influencing their choices.

• Observe and Take Notes

Watch for hesitation, confusion, or comments that reveal user thinking.

• Allow Time for Naming Groups

In open or hybrid sorts, participants should name their groups. This reveals their language and mental models.

Analyzing Card Sorting Results

After collecting data, analysis helps identify patterns and inform design decisions:

• Look for Common Groupings

Find clusters that most participants created similarly. These indicate natural categories.

• Use Similarity Matrices

Tools can generate matrices showing how often cards were grouped together, highlighting strong relationships.

• Review Group Names

Analyze the labels users gave groups to choose clear, user-friendly category names.

• Identify Outliers

Note cards that were sorted inconsistently. These may need clearer labeling or reconsideration.

• Combine with Other Research

Use card sorting results alongside user interviews, analytics, or usability testing for a fuller picture.

Card sorting data analysis displayed on a computer screen

Best Practices for Effective Card Sorting

To get the most from card sorting, follow these best practices:

• Keep Cards Manageable

Limit the number of cards to avoid overwhelming participants.

• Use Clear, Consistent Language

Ensure card labels and instructions are easy to understand.

• Test Your Cards Beforehand

Run a pilot session to catch confusing cards or instructions.

• Encourage Honest Grouping

Remind participants there are no right or wrong answers.

• Combine Qualitative and Quantitative Data

Note participant comments and use software tools for statistical analysis.

• Iterate Based on Findings

Refine your content structure and test again if needed.

• Document Everything

Keep detailed records of sessions, participant demographics, and results for future reference.

When to Use Card Sorting in Your Design Process

Card sorting fits best during early design stages when you define or refine information architecture. It helps:

• Design website navigation menus

• Organize product categories in e-commerce

• Structure content for apps or software

• Improve labeling and terminology

  
  

Avoid using card sorting alone for final decisions. Combine it with usability testing and other research methods to validate your design.

Final Thoughts on Card Sorting

Card sorting reveals how users think about content, making it easier to build intuitive and user-friendly structures. By choosing the right type, preparing carefully, and analyzing results thoughtfully, you can create navigation and categories that truly match user expectations.