Taxonomy / Categorization System

explorationmediumIntermediate

TL;DR

Content classification structure based on users' mental models.

What is it

A UX Taxonomy is a content, product, or feature classification and labeling system based on how users think and search for information — not on the organization's internal structure. It's fundamental for information architecture.

What it is for

✓Organize content or products according to user mental model
✓Improve findability
✓Define filter, category, and navigation structure
✓Standardize nomenclature across the product

Research methods that feed it

Card Sorting (open and closed)Tree TestingInternal search analysisMental model interviews

When to use it

✓When designing categorization for e-commerce or marketplace
✓When users can't find content with current structure
✓When migrating content from one system to another
✓To standardize vocabulary between teams and product

When NOT to use it

✗If content is very small (< 20 items)
✗Without prior user research on how they categorize
✗As a theoretical exercise without real user validation

How to create it step by step

1Inventory: List all content or products to categorize.
2Open Card Sorting: Ask 15-20 users to group items into categories that make sense to them.
3Analyze patterns: Identify categories most users created naturally.
4Define taxonomy: Create the hierarchical structure (main categories → subcategories → items).
5Validate with Tree Testing: Test if users find specific items in the new structure.
6Iterate and document: Adjust based on results and create a reference document for the team.

Tips for small teams

Use Optimal Workshop (free plan) for remote Card Sorting
8-10 Card Sorting participants give useful results
Start with 3 main categories and go deeper later
Document 'alternative labels' — they're useful for SEO and internal search

Common mistakes

✗Creating categories based on internal organizational structure
✗Not including alternative labels for items users call differently
✗Creating categories too broad or too specific
✗Not validating with Tree Testing after defining structure

Contextualized example

Context: Hardware store e-commerce with 3,000 products.

Before: Categories by brand and technical type (how suppliers organize). Users searched 'how to fix a faucet?' but category was called 'Sanitary faucets'.

After Card Sorting: Users organized by task ('Repair', 'Build', 'Decorate') not by product type. New main taxonomy: Projects by room → Task type → Product. Result: +25% findability.

Phase

exploration

Audience

product-teamdevelopment

Complexity

medium

Experience level

Intermediate

Related deliverables

Related methodologies

Free tool by UXR — UX Research Consulting in Chile