A trial is an individual instance of an experiment used to test different variations of the experiment settings. You can schedule up to 10 separate trials with different experiment periods and traffic allocations, then compare the results to see which performed best.
Trial experiment periods can't overlap with other trials on the same experiment. Trials can't be added to a completed experiment after you’ve made a decision about the experiment results.
Complete the following steps to add a trial to an existing experiment:
- Sign in to Google Ad Manager.
- Click Reporting Experiments.
- Click the experiment.
- Click Add trial.
- Select the experiment period. Set a start date and an end date for the experiment trial.
- Start date: Each trial needs to run for at least 7 days to improve the chance of reaching conclusive results. You can schedule a trial to start immediately, or specify a later date. All trials start at 12:00 am and end at 11:59 pm on the scheduled dates in your local time zone. Data is refreshed daily. If you set the start date to the current day, the trial will start within the next hour.
- End date: Each experiment trial can run up to 31 days total. When the trial ends, you can review and evaluate the results to decide whether you want to apply it as an opportunity, run another trial, or end the experiment and keep the original settings.
- Select the percentage of impression traffic to allocate to the experiment.
- Click Save.
Edit a trial
To edit a scheduled trial before it begins, click Edit Settings. You can edit the start and end dates of a scheduled trial up until the trial begins to run, at which point only the end date can be edited. Trials that have ended can't be edited.
View a different trial
To view a list of the trials already added to an experiment, click in the "Trials" section of an experiment. Select a trial from the list to display its current performance and status.