Ending an Experiment

Learn how to properly end experiments and make informed decisions based on your results.

Ending a Statsig experiment means choosing what happens to new users, to users already exposed, and to the experiment's results. You can ship a group to all users (Make a Decision), stop enrolling new users while exposed users keep their assignment (Stop Assignments), stop enrollment and data collection without shipping a group (Conclude Experiment and Defer Decision), abandon the experiment, reset it, or disable a single group. The following table shows which action fits each situation and where to find the details.

Choose how to end an experiment

Action	New users	Existing users	Results	Page
Make a Decision	Receive the shipped group's parameter values as the new defaults	Receive the shipped group's parameter values	Remain accessible but stop updating on the day you make the decision	Make a Decision
Stop Assignments	No new users enter; allocation drops to 0% and new users receive the project's default experience	Keep receiving their control or treatment experience (requires Persistent Assignment)	Analysis continues for already-exposed users	Stop Assignments
Conclude Experiment and Defer Decision	No new users enter	Receive the default experience	Data collection stops and results conclude; you can still ship, reset, or abandon later	Conclude Experiment & Defer Decision
Abandon	Receive the default experience	Receive the default experience	Experiment moves to a finished state; you can reset it later	Abandon an Experiment
Reset	Receive the default experience until you restart; the new salt reassigns groups on restart	Receive the default experience until you restart	Experiment returns to an unstarted state	Reset an experiment
Disable a group	Statsig can still assign new users to the disabled group; they receive the default experience	Users in the disabled group receive the default experience; other groups keep running	Statsig continues calculating results for the disabled group	Disable a Group

Make a decision

To ship any of the groups in your experiment, including control, to all your users, make a decision on the experiment. Making a decision ships the parameters of the selected variant to all users. If the experiment is in a layer, Statsig updates the layer defaults to reflect your shipped experience.

Stopping an experiment

If your experiment has a problem and you need to stop it, you have two options.

If the problem means you no longer want to run this test, abandon the experiment. Abandoning the experiment puts it in a finished state and all users fall back to the defaults in code. You can still reset it later if you decide to revisit the experiment.
If one of the groups has a bug you plan to fix and you want to restart the experiment later, reset the experiment. Alternatively, you can disable the group with the bug if you want to keep the other test groups running.

Reset an experiment

Resetting puts the experiment into an unstarted state. Every user receives the default experience, either the value defined in code or the layer default. The "salt" used to randomize a user's group also changes. When you start the experiment again, Statsig randomly assigns users to a group that isn't necessarily the same group they were in before the reset. This reassignment ensures that a bug or bad experience in the previous run doesn't negatively affect a group after you address the issue.

Archive an experiment

After you make a decision on an experiment, or when you abandon or reset it, you can archive the experiment. Archiving preserves the experiment's history and results and makes the experiment read-only.

If you later decide to make the experiment active again, unarchiving the experiment makes it editable but doesn't automatically restart it.

If the unarchived experiment was previously part of a layer and you intend to include it again, you must manually reset allocation from that layer.

Was this helpful?