Single-adgroup manual testing allows you to run tests with configuration different from the default used by the automated daily tests.  The configuration the manual test allows you to control are shown below and can be used as follows:

1) You can override the current thresholds values.  This affects only this test run and will not change your global thresholds values.  Automated tests always use the default account thresholds.

2) You can specify a date range other than 'common date range' which is what the automated tests always use.

3) You can include/exclude mobile-prefered ads.  Automated tests always include all ads within an adgroup.

4) In manual testing, you can choose to see all test results irrespective of confidence level.  Automated tests won't show any results where all metrics have less than 90% confidence.

Tip:  running a manual test with the default values shown below will generate the exact same result as the automated test.