Event Taxonomy

An event taxonomy is the agreed system for naming, structuring and organizing the events and properties a product tracks. It defines which user actions are recorded, what each event and property is called, which values properties may hold and how everything fits together, so every team reads the same data the same way and reports stay comparable over time.

How an Event Taxonomy Works

A taxonomy covers three building blocks. Events are actions a user takes, such as "Project Created". Event properties describe a single occurrence, such as the template used for that project. User properties describe the person and apply to all their future events, such as plan type or role.

Around these blocks, the taxonomy sets rules:

• A naming convention. Analytics vendors recommend a consistent object and action pattern. Mixpanel calls it the Object-Action convention, with examples like "Post Created" and "Purchase Completed". Amplitude's data planning guide recommends a noun followed by a past-tense verb, such as "Product Added".
• Consistent casing. Analytics tools usually treat names literally. Amplitude notes that "Song Played" and "song played" appear as two separate events, which splits the data.
• Properties over new events. Instead of separate events for each variation, use one event with a property. One "Order Completed" event with a payment method property scales better than a new event for every payment method.
• Shared property definitions. A property such as "plan" should mean the same thing, with the same allowed values, on every event that carries it.

The taxonomy is usually documented in a tracking plan, a shared reference listing every event, its properties, a plain-language description and an owner. Mature teams also add governance: a review step before new events are added and statuses such as proposed, active and deprecated, so changes do not silently break existing reports.

Why an Event Taxonomy Matters

Without a taxonomy, data quality decays as more people add tracking. Different engineers name the same action differently, web and mobile apps disagree, and analysts spend their time reconciling duplicates instead of answering questions. Dashboards built on inconsistent events give conflicting numbers, and people stop trusting the data.

A clear taxonomy makes event tracking cheaper to extend and makes reports such as funnel analysis reliable across platforms. It also makes data self-serve: a product manager can find "Invoice Sent" in a list and know what it means without asking an engineer.

Event Taxonomy Example

A note-taking app tracks sign-ups as "signup" on the web, "Sign Up" on iOS and "user_registered" from the backend. Its activation funnel undercounts users because each chart picks up only one of the three names. The team defines a taxonomy: Title Case, object then past-tense action, and a "platform" property on every event. The three sign-up events are merged into a single "Account Created" event with platform values of web, iOS and server. New events must be added to the tracking plan, with a description and an owner, before they ship.

Event Taxonomy vs. Event Tracking

The two terms are related but not interchangeable. Event tracking is the implementation: the code that captures actions and sends them to an analytics tool. An event taxonomy is the design: the vocabulary and structure that tracking should follow. A team can track many events with no taxonomy, but the result is usually data that is hard to query and easy to misread.