Making conclusions about your metrics impact during set review periods reduces the chance of errors and allows you to account for seasonality in your data. Split always shows your current metrics impact and if you are between review periods. The images below show the two different states of incomplete and complete.
As a best practice, avoid making conclusive product decisions in between review periods or at a minimum ensure that you have run for at least one review period.
The review period can be incomplete for two reasons:
(1) Your split did not run for the minimum review period configured for your organization
(2) Your split is currently running and is between review periods
The review period is complete when the split has run for the minimum review period, set by your organization in either a current or previous version of your split. A 14-day review period (configured by default) is ready for review on day 14, 28, 42, and so forth.
If you believe that the default review period for your organization is too long or too short, you can reach out to your administrator to adjust your statistical settings.