The Sensemaker’s Guide to Controlled Vocabularies - Abby Covert, Information Architect

Have you ever been in a meeting where half the room calls something a “segment” while the other half calls it an “clip”? Or maybe you’ve built a navigation menu where the same content could logically fit under multiple labels, depending on who is doing the sorting? If you’re nodding your head right now, you’ve felt the pain that comes from messy language. The good news? There’s a tool for that.

Today we’re diving into controlled vocabularies – one of the most powerful yet often overlooked tools in our sensemaking toolkit. Let’s cut through the confusion together.

This article covers:

What is a Controlled Vocabulary in Sensemaking?

A controlled vocabulary is simply an agreed-upon set of terms that a group uses consistently. It’s a list of words that everyone promises to use the same way, to mean the same things. No fancy jargon needed.

Think of it as a language contract that says, “When we say X, we all agree it means Y – not Z.”

At its core, a controlled vocabulary helps groups of people speak the same language, even when they come from different backgrounds or departments. It’s the difference between talking past each other and truly connecting.

Reasons to Use Controlled Vocabularies

Why bother with all this word-wrangling? Here’s the straight talk:

Clearer communication. When everyone uses the same words to mean the same things, we waste less time explaining ourselves.
Better findability. Content, data, and information become much easier to find when everything is labeled consistently.
Reduced confusion. Those painful “wait, what do you mean by that?” moments happen less often.
Simpler onboarding. New team members can get up to speed faster when there’s a shared language in place.
More accurate data. Reports, analytics, and insights improve when we’re all tracking the same things under the same names.
Less rework. How many hours have you lost to misunderstandings that could have been prevented with clearer terms?

Common Use Cases for Controlled Vocabularies

You might be surprised at how often controlled vocabularies show up in your work:

Navigation systems: Ensuring menu items and labels make consistent sense across an entire website
Content tagging: Helping writers and editors apply consistent categories and tags
Data entry: Making sure everyone fills out forms with comparable information
Search systems: Improving the accuracy of search results by connecting related terms
Product catalogs: Organizing products in ways that customers can actually find them
Knowledge bases: Making information retrievable across teams and departments
Project management: Ensuring everyone understands workflow status labels the same way
Industry standards: Creating shared understanding across organizations (think medical terminology or legal documents)

Types of Controlled Vocabularies

Not all controlled vocabularies work the same way. Here are the main types you’ll encounter:

Simple Lists are exactly what they sound like – straightforward collections of preferred terms. These work well for smaller sets of words that don’t have complex relationships (like acceptable status values: “draft,” “in review,” “approved”).

Synonym Rings connect different words that mean basically the same thing. They help people find what they need regardless of the specific term they use (like connecting “car,” “automobile,” and “vehicle”).

Taxonomies organize terms into parent-child relationships, creating hierarchies that show how concepts relate. They’re perfect for organizing content into broader and narrower topics (like Animals → Mammals → Cats → Domestic Cats).

Thesauri are like taxonomies but include not just hierarchical relationships but also associative ones – terms that relate to each other but aren’t directly above or below each other. They often include scope notes that explain exactly how to use each term.

Ontologies are the most complex type. They define concepts, their properties, and the relationships between them with extreme precision. They’re often used in artificial intelligence systems to represent knowledge.

Approaches to Creating Controlled Vocabularies

There are a few ways to build a controlled vocabulary, and the right approach depends on your situation:

Top-down approach: Start with high-level categories determined by experts, then work down to more specific terms. This works well when you have clear domain knowledge and defined requirements.

Bottom-up approach: Begin by gathering the actual terms people are already using, then organize them into patterns. This is great when you’re working with existing content or want to align with how people naturally talk.

Hybrid approach: Most successful vocabularies combine both methods – using expert guidance while also respecting how users actually think and talk about things.

Collaborative approach: Involving stakeholders from across your organization often leads to vocabularies that are more likely to be adopted. When people help build it, they’re more likely to use it.

Borrowed approach: Sometimes the smartest move is to adopt an existing industry standard vocabulary rather than creating your own. Why reinvent the wheel?

Tips to Getting Started with Controlled Vocabularies

Ready to bring some order to the chaos? Here’s how to begin:

Start small. Pick one area where terminology confusion causes real problems, rather than tackling everything at once.
Listen first. Before prescribing terms, take time to understand what words people are already using and why.
Focus on painful points. Target the terms that cause the most misunderstandings or wasted time when used inconsistently.
Document everything. A controlled vocabulary only works when it’s written down somewhere accessible – not just in your head.
Include definitions. Don’t just list terms; explain exactly what each one means and how it should be used.
Plan for governance. Decide upfront who can add, change, or remove terms, and how that process will work.
Build in feedback loops. Language evolves, so create ways for people to suggest improvements or request new terms.
Think about format. Will a simple spreadsheet do the job, or do you need specialized tools to manage your vocabulary?
Consider maintenance from day one. Controlled vocabularies need upkeep. Who will own that responsibility long-term?
Communicate the value. Help others understand how consistent language will make their work easier, not just add another rule to follow.

Controlled Vocabulary Hot Takes

Let me share a few things I’ve learned the hard way:

Perfect is the enemy of useful. An imperfect vocabulary that people actually use beats a perfect one that sits in a document nobody opens.
Force rarely works. You can’t usually mandate language by decree. Focus on making your vocabulary so helpful that people want to use it.
The goal is clarity, not control. Despite the name, successful controlled vocabularies are more about creating shared understanding than policing language.
Natural language will always be messy. No controlled vocabulary will eliminate all ambiguity – and that’s okay. We’re aiming for “better,” not “perfect.”
Technology alone won’t save you. The fanciest taxonomy tool in the world won’t help if you haven’t done the human work of reaching agreement first.

Controlled Vocabulary Frequently Asked Questions

How big should my controlled vocabulary be? Only as big as necessary to solve your specific problems. Start small and grow as needed.

What’s the difference between a taxonomy and a controlled vocabulary? A taxonomy is a type of controlled vocabulary – specifically one that organizes terms into hierarchical relationships.

Who should be responsible for maintaining our controlled vocabulary? Ideally, someone who understands both the subject matter and how language works. Often this falls to information architects, content strategists, or librarians.

How do I get people to actually use our agreed-upon terms? Make it easy (build the vocabulary into tools where possible), make it visible (keep it accessible), and make it valuable (show how it solves real problems).

How often should we update our controlled vocabulary? Plan for regular reviews – perhaps quarterly for active areas. But also create channels for immediate feedback when urgent issues arise.

What tools should we use to manage our controlled vocabulary? It depends on size and complexity. A spreadsheet or shared document works for smaller vocabularies, while dedicated taxonomy management software might be needed for larger efforts.

Language is how we make sense of the world together. When we’re careless with our words, we create unnecessary confusion. Controlled vocabularies give us a practical way to build shared understanding – not by restricting creativity, but by creating a foundation of clarity that actually enables more meaningful work.

Whether you’re wrestling with inconsistent product categories, tangled metadata, or team members who seem to be speaking different languages, a thoughtful approach to vocabulary can transform chaos into clarity.

If you want to learn more about my approach to controlled vocabularies, consider attending my workshop on June 20th from 12 PM to 2 PM ET. Word Choice Wars: Building Controlled Vocabularies That Work — this workshop is free to premium members of the Sensemakers Club along with a new workshop each month.

Thanks for reading, and stay tuned for our focus area in July – Designing with Metadata.