Once I create and test it, how can I clear my survey data and start fresh?
There are two options:
You can create a clone of your PollUnit in the "My PollUnits" section. This does not yet work for PollUnits about images.
As a premium user You can delete entries from Your PollUnit: Visit the admin link of the PollUnit and click on the clear icon next to each participant.
It is now also possible to delete all participants from a PollUnit. As admin and premium user you can click on "Delete all participations" in the context menu (three dots).
I have created a poll for images with Rating options.
I want to delete some of the ratings from dummy users, how can i do that?
you can go to Evaluation - Participants and there you can delete the single participants which are dummy users.