Determine a hypothesis to test

Before setting up a Split Test, determine what you are trying to test and how that can help inform your ad strategy. Thinking about your hypothesis will help you focus on what variable to test and ensure you design and run a "clean" A/B test.

Set up test groups with large differences in variables

When choosing your testing variable, we recommend that the settings for the two test groups differ significantly. There should be obvious differences to ensure the two ad groups don't produce similar results so the system can determine a winning ad group.

Set an appropriate test budget

The budget for your Split Test should produce sufficient results to give you confidence in identifying the best performing strategy. When you create a Split Test, the system will demonstrate the Estimated Testing Power based on the budget you set. Make sure that your budget shows that the Estimated Testing Power is sufficient.

Allocate an adequate testing duration

We recommend testing for a minimum of 7 days to obtain the most reliable results. Split Tests can run for a maximum of 30 days. Testing for less than 7 days may not be long enough to determine a winner, while long testing may lead to a shortfall in the budget.

Set a large audience

It is recommended that you expand your audience to avoid an insufficient sample size when running a Split Test.

Ensure a higher estimated Power Value

Power Value is the likelihood of detecting potential differences in your ad group which helps determine your chances of finding a winning result. We recommend a budget that gives you a Power Value of at least 80%.

Avoid mid-test changes

Making changes to your ad group after your Split Test started running may impact its results or cause the ad group to go into review again. It is recommended that you don't change your Split Test settings after it has started running.