Configuring experiment analytics

This skill answers: Who is included in the analysis? and How to measure impact?

Exposure criteria

Exposure criteria determine which users are counted in the experiment analysis.

Exposure event

Two options:

1. Default exposure event — users are included when the experiment's default exposure event fires for the experiment's flag: $feature_flag_called, or $experiment_exposure for newer experiments. Which one applies is resolved server-side — read resolved_exposure_event from experiment-get rather than assuming either name (both events carry the same properties). When it is $feature_flag_called, also read $experiment_exposure (event IN ('$feature_flag_called', '$experiment_exposure')), and count persons, not rows. This is the standard approach — it means a user is included only when they actually encounter the feature flag in your code.
2. Custom exposure event — users are included when a specific custom event fires. Use this when you want tighter control over who enters the analysis (e.g., only users who actually visit the page where the experiment runs).

Filters on the exposure event remove individual events, not users. A user still counts as long as one of their exposure events passes the filters. To keep users out of the experiment, exclude them in the flag's release conditions before launch (see configuring-experiment-rollout).