I have users' reports about an accident. I want to know how to make sure that the number of reports is big enough to take that accident as a true accident and not spam.
My idea is to consider a minimum number of reports in a specific time interval, for example 4 reports in 20 minutes are good enough to believe the existence of that accident.
My question is how can I choose the minimum number of reports and that time interval? Is there some logic to make that decision?