I have a survey built which will be going out via anonymous link. We will not be collecting any identifiable data. Because the survey will be distributed by many participating organizations - we know that there will likely be overlap in respondents. To prevent duplicate responses - we are working on setting up an email authenticator which (when programmed correctly) will ask for an email - add that email to a directory through workflow at the completion of the survey and then use that directory as a source for the authenticator - not allowing someone who has been added to the directory (by completing the survey) to start the survey again.However - the survey currently is not allowing anyone to move past the email input - immediately displaying a ‘Unable to log in with the information provided.’ error message (even in incognito mode). I checked the directory and it is not adding emails there either. Please help!-Marta

I also struggle with duplicates in open surveys, so I'll give this approach a try as well

Reverse Autheneticator - prevent multiple responses from the same participant using their mail in anonymous surbey.

Reverse Autheneticator - prevent multiple responses from the same participant using their mail in anonymous surbey. | Experience Community