Anti Ballot Box Stuffing (ABBS) based on Custom Variables feature prevents a user to take multiple responses of a survey.
How to enable ABBS based on Custom Variables feature?
To enable ABBS based on Custom Variables on a survey follow the steps below:
Survey >> Edit >> Settings
Select the second radio button under
Switch "Use a custom variable to identify responses" toggle ON
Select the custom variable form the dropdown on which you have to enable ABBS
Background Processing (for better understanding):
ABBS is triggered when the survey is completed for the first time. If the respondents start the survey and do not complete it, they can still access the survey by clicking on the link that they have got via email.
Just to reiterate, link will get disabled once the respondent completes the survey. If they complete the survey and again try to access the same link, they will get an error message as displayed below:
If the respondent answered the survey with the help of custom variable attached survey link in a browser window and then tries to access the same link again with same or different custom variable data with previous browser window not closed then he/she will get the same error message as above.
This feature is available with the following licenses :