Open Card Sorting

Open Card Sorting: Uncovering User Mental Models for Better Information Architecture

Open card sorting is a user research technique used to understand how users categorize and organize information. By allowing participants to group and label content in ways that make sense to them, designers can gain valuable insights into users’ mental models, leading to more intuitive and user-friendly information architecture.

What is Open Card Sorting?

Open card sorting involves providing participants with a set of cards, each representing a piece of content or information. Participants are asked to sort these cards into groups that they find meaningful and then label each group with a name that they think best describes the content. Unlike closed card sorting, where categories are predefined, open card sorting allows users to create their own categories, providing deeper insights into their thought processes.

Importance of Open Card Sorting in UX Design

  1. User-Centered Design: Open card sorting helps ensure that the information architecture reflects the way users naturally think about and categorize information.
  2. Improved Usability: By aligning the structure of a website or application with users’ mental models, designers can create more intuitive navigation and improve overall usability.
  3. Insight into User Behavior: This technique provides insights into how different users perceive and organize information, highlighting potential areas of confusion or misalignment.
  4. Validation of Assumptions: Open card sorting allows designers to validate or challenge their assumptions about how information should be organized, leading to more effective design decisions.

Key Principles of Effective Open Card Sorting

  1. Clear Instructions: Provide participants with clear, concise instructions on how to sort and label the cards. Ensure they understand that there are no right or wrong answers.
  2. Representative Content: Select a representative sample of content that covers the key areas of the site or application. Avoid overwhelming participants with too many cards.
  3. Diverse Participants: Recruit a diverse group of participants that reflects the target user base. Different perspectives can reveal varied mental models and categorizations.
  4. Facilitation and Observation: Facilitate the session by guiding participants and answering questions, but avoid influencing their decisions. Observe their sorting process to gain additional insights.
  5. Analysis and Synthesis: Analyze the results to identify common patterns and groupings. Use these insights to inform the design of the information architecture.

Best Practices for Conducting Open Card Sorting

  1. Use Online Tools: Tools like OptimalSort, UXtweak, and UserZoom provide platforms for conducting open card sorting sessions online, making it easier to gather and analyze data.
  2. Pilot Testing: Conduct a pilot test with a small group to ensure the instructions are clear and the process runs smoothly. Adjust the instructions or card set if necessary.
  3. Encourage Thinking Aloud: Ask participants to think aloud as they sort and label the cards. This provides valuable context and reasoning behind their decisions.
  4. Document Sessions: Record the sessions or take detailed notes to capture participants’ thought processes and any additional insights that may arise.
  5. Iterative Approach: Use open card sorting as part of an iterative design process. Conduct multiple rounds of sorting and refine the information architecture based on user feedback.

Tools for Conducting Open Card Sorting

  1. OptimalSort: A popular tool for conducting both open and closed card sorting studies online, providing robust analysis and reporting features.
  2. UXtweak: An online user research platform that offers card sorting, tree testing, and other usability testing tools.
  3. UserZoom: A comprehensive UX research platform that includes card sorting, usability testing, and surveys to gather user insights.
  4. UsabilityTools: Provides a range of usability testing and user research tools, including card sorting, to help design user-centered information architecture.
  5. Miro: An online collaborative whiteboard platform that can be used for virtual card sorting sessions, allowing for real-time collaboration and feedback.

Real-World Examples

  1. E-commerce Websites: Open card sorting can help e-commerce sites like Amazon or eBay organize product categories in ways that make sense to users, improving navigation and searchability.
  2. Corporate Websites: Companies like Microsoft or IBM can use open card sorting to structure their corporate websites, ensuring that information about products, services, and support is easily accessible.
  3. Educational Platforms: Online learning platforms like Coursera or Khan Academy can benefit from open card sorting to categorize courses and resources in a way that aligns with users’ expectations.
  4. Healthcare Websites: Health information websites can use open card sorting to organize content about conditions, treatments, and wellness resources in a user-friendly manner.
  5. Library Systems: Public or academic libraries can employ open card sorting to organize digital catalogs, making it easier for users to find books, articles, and other resources.


Open card sorting is a valuable user research technique for designing intuitive and user-centered information architecture. By allowing users to create their own categories and labels, designers can gain deep insights into users’ mental models and ensure that the structure of a website or application aligns with their expectations. Implementing best practices and using appropriate tools can help achieve meaningful results and enhance the overall user experience.

Ondrej Zoricak
Ondrej Zoricak