Before fielding, you typically want to test out the flow to make sure that everything runs smoothly. After running test sessions, you want those sessions do not get mixed in with the real results.
There are two ways to exclude the sessions from the experiment.
When setting up the experiment
Once you confirm that everything is working correctly, you can go ahead and exclude all your test sessions by ticking check the box in the column titled “Exclude”. This will exclude all of your test sessions from the data when the experiment is completed. You can then proceed to next step and launch your experiment.
While the experiment in progress or completed
On the "Participants" page there is the same list of all the participants that have entered the experiment. Find the sessions that you need to exclude and tick the box in the “Exclude” column.