Hey @dread pirate. Welcome to the Typeform Community! 

Yes, they can. If the respondent simply opens the form and submits it again, another submission will be considered. Would you have a specific use case to share with us? This way, we'll be able to advise further. :) 

Hey @Mariana Thank you. I have a survey out to a client group and they were worried that someone in their organization could purposely skew the results by submitting multiple times. They asked me if that was true or if we would even know if it happened. Do you know?

@dread pirate - from a user here, with a potential similar situation 

I have been discussing with a client about this issue and there are a couple of potential workarounds that might work in my case, and perhaps in yours:

• asking for an email address to be submitted with each response and then using an integration with Google Sheets to manage duplicate entries coming from the same email address
  • doesn’t really work if you want it to be anonymous but does give you the ability to filter out the duplicate entries
• if a new survey, can use hidden field with email address of recipient/respondent in the URL/link to the survey that they receive in an email 
  • this is similar to the prior point and can be done in the back end of the analytics
• you could establish with the client group how many individuals should be responding to the survey (ie 50) and set the Access limit for that number of responses plus a margin of safety - see the image below
  • client could poll intended respondents for how many have completed and based on the ‘not yet’ poll, you should be able to tell how many have duplicate entries have been if they have hit the limit of say 55 but 15 have yet to reply.. (indicates that about 20 duplicate entries have been made - 50 minus 15) 

while this is not a perfect solution set to the problem, these are the things I am currently reviewing with a client that might resolve the issue

des

Wow, this is great! Thanks @john.desborough !

Thanks @john.desborough I have considered having the respondents give their email but my group crosses all generations and I was worried about possible reluctance to give that out… Maybe your second option solves this? I’, not familiar with that approach but will try to look around for how to do that.

https://help.typeform.com/hc/en-us/articles/360052676612-How-to-use-Hidden-Fields 

check that article as it explains how to use hidden fields. maybe that will help to shed some light

des