Open vs Closed Card Sorting: Complete Comparison
Quick Summary
Winner: Hybrid Card Sorting for most users because it combines the exploratory benefits of open sorting with the validation aspects of closed sorting.
However, if you're in the early discovery phase of your project, Open Card Sorting might be better. If you're testing an established information architecture, Closed Card Sorting could be more appropriate.
Both methods serve different research purposes, so your specific project needs will ultimately determine which approach is best for you.
Feature Comparison
Feature | Open Card Sorting | Closed Card Sorting | Hybrid Card Sorting |
---|---|---|---|
Categories | Participants create their own | Pre-defined by researcher | Mix of pre-defined and user-created |
Research phase | Early discovery | Validation | Mid-stage development |
User freedom | High | Low | Medium |
Analysis complexity | Higher | Lower | Medium |
Time required | More | Less | Medium |
Sample size needed | 15-30 participants | 10-20 participants | 15-30 participants |
Learning curve | Steeper for analysis | Easier to analyze | Moderate |
Best for | Discovering mental models | Testing existing structures | Refining and expanding structures |
What is Open Card Sorting?
In open card sorting, participants are given a set of content items (cards) and asked to organize them into categories that make sense to them. Crucially, participants also name these categories themselves. This approach reveals how users naturally group and label content, uncovering their mental models without imposing predefined structures.
Pros: ✅ Reveals authentic user mental models ✅ Discovers unexpected category patterns ✅ Generates organic, user-centered terminology ✅ Highly exploratory and open-ended ✅ Excellent for early-stage projects
Cons: ❌ Results can be messy and varied ❌ Analysis is more time-consuming ❌ May require larger sample sizes ❌ Can be overwhelming for participants ❌ Categories might not align with business needs
What is Closed Card Sorting?
Closed card sorting provides participants with predefined categories. Users then sort content items into these fixed categories. This method tests and validates existing or proposed information architectures rather than generating new ones.
Pros: ✅ Easier and faster to analyze results ✅ Tests specific hypotheses about categorization ✅ Validates existing or planned structures ✅ More controlled experiment environment ✅ Requires fewer participants for reliable results
Cons: ❌ Doesn't reveal new category ideas ❌ May force content into ill-fitting categories ❌ Can miss natural user mental models ❌ Less useful for discovery ❌ May reinforce existing biases in categorization
What is Hybrid Card Sorting?
Hybrid card sorting (sometimes called "semi-closed" or "modified" card sorting) combines elements of both methods. Typically, participants are given some predefined categories but can also create their own. This approach balances validation with discovery.
Pros: ✅ Combines benefits of both methods ✅ Validates existing categories while allowing new ones ✅ More flexible than closed sorting ✅ More structured than open sorting ✅ Good for iterative improvement of existing architectures
Cons: ❌ Can be confusing for participants ❌ Analysis is moderately complex ❌ May require careful facilitation ❌ Results can be harder to interpret ❌ Requires balancing predefined and user-created categories
When to Use Open Card Sorting
Open card sorting shines in these scenarios:
- Early-stage projects when you're just beginning to understand how users conceptualize your content
- Complete redesigns where you want to start fresh without assumptions
- New product development when mental models are unknown
- Exploratory research to discover unexpected patterns
- Terminology development to understand what labels make sense to users
For example, if you're designing a new e-commerce platform and aren't sure how to organize your product catalog, open card sorting can reveal natural product groupings that make sense to your target customers.
When to Use Closed Card Sorting
Closed card sorting works best in these situations:
- Testing existing information architecture to identify problem areas
- Validating proposed structures before implementation
- Comparing multiple potential structures to determine the most intuitive
- Later-stage development when refining rather than creating
- When categories are fixed due to business or technical constraints
If you already have an established website navigation but suspect users struggle to find certain items, closed card sorting can test whether content belongs in your existing categories or needs reorganization.
When to Use Hybrid Card Sorting
Hybrid approaches are ideal when:
- Refining an existing structure while being open to new ideas
- Partially established categories exist alongside areas of uncertainty
- Balancing business requirements with user preferences
- Iterative improvement of information architecture
- Testing comprehension of main categories while exploring subcategories
For instance, if you have established top-level navigation categories but are unsure about subcategory organization, a hybrid approach lets you validate the main categories while discovering optimal subgroupings.
Best Practices for Card Sorting
Regardless of which method you choose, these practices will help ensure successful results:
For Open Card Sorting:
- Use 30-50 cards for optimal results (too many overwhelms participants)
- Recruit 15-30 participants for reliable patterns
- Use clear, concise card labels
- Consider running multiple rounds to refine findings
- Look for clusters and patterns rather than exact matches
For Closed Card Sorting:
- Ensure category labels are clear and distinct
- Include a "doesn't fit" option for problematic items
- Keep category count reasonable (5-10 is typical)
- Aim for 10-20 participants for validation
- Consider A/B testing different category sets
For Hybrid Card Sorting:
- Clearly explain that participants can both use and create categories
- Make the "create new category" option obvious
- Keep pre-defined categories minimal to avoid overwhelming participants
- Analyze both category usage and creation patterns
- Follow up with interviews about category creation decisions
The Verdict
When to choose Open Card Sorting: Choose open card sorting when you need to discover how users naturally conceptualize and organize your content. This method is invaluable for early-stage projects, complete redesigns, or when developing user-centered terminology.
When to choose Closed Card Sorting: Opt for closed card sorting when validating existing structures, testing specific hypotheses about content organization, or when categories are constrained by business requirements. This method provides clearer, more actionable results for established architectures.
When to choose Hybrid Card Sorting: Select hybrid card sorting when you have some established categories but want to remain open to user input, when refining rather than creating or validating structures, or when balancing business needs with user perspectives.
The best approach often involves combining methods across your research timeline: start with open sorting for discovery, refine with hybrid approaches, and validate with closed sorting.
Run Your Own Card Sort Today
Ready to improve your information architecture with card sorting? Free Card Sort offers all three methodologies—open, closed, and hybrid card sorting—with no participant limits and straightforward analysis.
Whether you're discovering new mental models with open sorting, validating structures with closed sorting, or finding the middle ground with hybrid approaches, Free Card Sort provides the tools you need to make informed IA decisions.
Get started today and discover how your users naturally organize your content, no credit card required!