The cheapest version: a Google Forms survey, it's a starting point, but it does not validate a behavioral trend at 75%. This type of survey is useful for a quick idea, not for such precise numerical claims about document verification habits.
To understand why people verify their papers, more in-depth interviews are needed, not just checkbox questions, because motivations are complex.
For example, relying on a small survey to claim that three-quarters of people do something is like judging the weather of an entire region by looking through a single window one morning.
It's a light method that does not capture the real nuances influencing the decision to verify early or late.
It underestimates unforeseen events or practical constraints that force some to act at the last minute.