Card Sorting

Card sorting is a user experience research method that helps you discover how people understand and categorize information. Participants organize topics into groups that make sense to them, revealing their mental models.

How It Works

1. Create cards representing content items
2. Participants sort cards into groups
3. Participants may name groups (open) or use your categories (closed)
4. Analyze patterns across all participants
5. Use insights to design navigation and IA

Types of Card Sorting

Open card sort: Participants create their own category names

• Best for: Discovery, new projects
• Reveals: Natural mental models

Closed card sort: Sort into predefined categories

• Best for: Validation, comparing options
• Reveals: Whether your categories work

Hybrid card sort: Suggested categories + option to create new ones

• Best for: Refinement with flexibility
• Reveals: Validates ideas while staying open

Why Card Sorting

Understand users: How they think about your content Better navigation: Based on real user mental models Right labels: Use words users actually use Reduce assumptions: Test instead of guessing Stakeholder buy-in: Data beats opinions

When to Use Card Sorting

Early stage: Designing new IA from scratch Redesign: Improving existing navigation New features: Adding content to existing structure Validation: Testing proposed categories Internationalization: Understanding different markets

Sample Size

Open card sorting: 20-30 participants Closed card sorting: 30-50 participants Hybrid: 25-40 participants

More participants = clearer patterns

What You Learn

Natural groupings: Which items belong together Category names: What users call groups Outliers: Items that don't fit anywhere Disagreements: Where users don't align Mental models: How users think about your domain

Card Sorting Process

1. Define scope: What content to include
2. Create cards: 30-60 items typically
3. Recruit participants: From target audience
4. Run study: Online or in-person
5. Analyze results: Dendrograms, similarity matrix
6. Design IA: Based on insights
7. Validate: Tree testing

Common Mistakes

❌ Too many cards (60+ is overwhelming) ❌ Too few participants (less than 15) ❌ Wrong participants (not target users) ❌ Implementing results without validation ❌ Ignoring outliers (they're often insightful!)

Best Practices

✅ Use clear, concise card labels ✅ Avoid jargon and acronyms ✅ Include diverse participants ✅ Combine with other research methods ✅ Test your findings (tree testing) ✅ Iterate based on results

Card Sorting Tools

Online tools (like Free Card Sort):

• Remote participants
• Larger sample sizes
• Automatic analysis
• Faster results
• Free at freecardsort.com!

In-person:

• Physical cards or digital
• Qualitative insights
• Can ask "why"
• Smaller samples

Start your free card sort today at freecardsort.com