Events from paused experiments, stopped variations, and archived experiments

  • Updated
  • Optimizely Web Experimentation
  • Optimizely Performance Edge

If you pause an experiment, you must consider the change in user experience for visitors who are bucketed into that experiment.

Paused experiments

If you pause a running experiment, the variation code is removed from the snippet. This means that the experiment and variation code can no longer run on the page because the code is removed from the snippet.

  • New visitors are not evaluated for the experiment. This means that no new visitors are bucketed into the experiment after the experiment is paused.

  • Visitors already bucketed into the experiment while the experiment was running see the native web page, with no experiment or variation code added.

  • Events with timestamps within the experiment's timeframe are still recorded even after an experiment is paused. This can occur if visitors leave the page too quickly and then return to the browser later on
  • Events sent through the Event API are recorded if they have timestamps within the experiment period, even if they are sent after the experiment is paused.

Restart paused experiments

If you restart a paused experiment, the experiment and variation code are added back to the snippet. Visitors bucketed into the experiment while it was initially active see the variation they saw before. Returning visitors are not re-bucketed into a new variation because their bucketing information is stored locally in their browsers and does not change if the experiment is paused.

Optimizely Experiment Results page

When an experiment is paused, the results page may continue to update with new data if the events have timestamps within the experiment's active period, despite the experiment being paused. This is particularly relevant for events sent in batches, which might arrive after the experiment is paused, but still need to be reflected in the results. 

While an experiment is paused, bucketing decisions are not collected for events scoped to the experiment. The results page may show a gap when the experiment was paused.

Network events

Visitors already bucketed into the experiment can continue to trigger events while the experiment is paused. If you were testing your experiment and were bucketed into it while it was running, then certain events (specifically, pageview, click events scoped to the page, and custom events) continue to trigger and are visible in the Network tab of your browser.

Events scoped to the experiment do not trigger when an experiment is paused. Only pageview events, click events scoped to a page, and custom events are sent to Optimizely when an experiment is paused. These events are not visible on the results page. 

Stopped variation

If you stop a variation but do not stop the experiment, Optimizely removes both the variation code and the variation ID from the snippet and leaves the experiment and any other variation information intact when a variation is stopped.

  • New visitors are evaluated by Optimizely Web Experimentation for the experiment and bucketed randomly into the remaining variations. This means no new visitors are bucketed into the stopped variation.

  • In Optimizely Web Experimentation, visitors who were already bucketed into the stopped variation see the native web page with no experiment or variation code added.

  • In Optimizely Performance Edge, visitors who were bucketed into the stopped variation are re-bucketed into another variation in the experiment.

When you stop a variation, you cannot restart it.

Optimizely Experimentation Results page

The results page continues to collect data for the experiment. However, you should expect conversions for the stopped variation to decline.

Updating visitor bucketing information

Visitors bucketed into the stopped variation continue attributing events to the results page until they return to a URL where the experiment is active. Then, bucketing information updates, and the variation ID is removed. At that point, events are no longer attributed to the variation ID on the results page.

Network events

If you are testing a stopped variation, you may see events triggered in the Network tab of your browser. Go to the page where the experiment activates and expand the network event. If the variationId is null, the bucketing information is updated.

Archived experiments

When an experiment is archived, the results page records a new stop date and time and ceases tracking events for the experiment. See manage experiments and campaigns in Optimizely Web Experimentation.