To clear the results and reset all the responses of a survey :
Please Note: Using this option will delete all data for the Survey. Do not use this option if you have started live collection of data. Data once deleted cannot be retrieved!
Why would I want to clear the data?
If you are doing pre-test trials etc. you usually want to clear out all the test data from the database before starting to collect "real" data. Use the "Clear Data" function for this.