Hi ​@HIOW ICB 

If someone answers just a few questions, sends it in, and then would later like to come back to fill in the rest of the questions, this can be handled easily if they use the same device. With the use of cache and cookies, the participants are remembered for a week so using the same device/browser within this span would get them back. Also, if you require emails from people when they enter the slido, they would be able to only edit their previous survey instead of adding a new submission, no matter what device or how much later they would do so.

In case you would like for the people to answer all the questions at the same time and not at multiple times, you can set up the questions in the survey as mandatory.

Hope this helps!

Best,