I will conduct an online survey targeting both students and their parents. The parent survey is distributed through the school managers and the students take the survey within their school. Our objective is to guarantee that the parent survey is exclusively completed by parents, without any involvement from students.

we are  looking for measures to prevent students from accessing and completing the parent survey. By looking at the patterns, can we determine that the student filled out his own survey and the parent filled out his own survey? 

More clearly: Can we detect any behavioral as well as answer similarity across student and parent survey? 

Or is there any other method you could provide to address this issue such that students don’t attempt to take the parental survey?