Notes / Families

When to split an event family

19 January 2026

Desk with planning documents for a taxonomy split

Teams add checkout_started_v2 because they are afraid of breaking a dashboard. Fear is not a taxonomy. In the Event Family Studio we only split a family when the object changed, the actor changed, or the success condition changed — not when a designer shipped a new illustration.

The three-question test

Would a new analyst expect these rows in the same table? Do properties still mean the same thing? Can one funnel step list hold both? If any answer is no, split. If all are yes, add a property such as surface or step.

Suffixes

_new, _final, and _really_final are how catalogues die. Dual-write the new name, annotate the old, and put a retirement date in the RFC. The volume pass later tells you whether the old name still fires from a forgotten tablet build.

Splitting too early is also a cost: two families means two owners. We have declined catalogue work where a director wanted a new family for every experiment. Experiments belong in properties or in a separate research stream, not in the production grid.