You can delete your respondents' answers as well as those entered in Preview mode. To do so, go to the "Results" module of your questionnaire, and click on the "Results per respondent" tab:
To delete only responses registered in Preview mode, click on "Delete responses made in Preview mode".
Please note: by clicking on this button, all responses made in Preview mode will deleted.
In order to delete your respondents' responses, tick the resports you wih to delete and click on "Delete Respondents". If you wish to delete all the respondents located on one page, tick the box located on the left of "Start date" and click on "Delete Respondents".