The cheapest version: an online survey, even well-made, does not replace a solid study on travel habits.
Claiming that 75% of people verify their identity documents well in advance based on just 78 responses is a bit of a quick conclusion, without more context.
In Canada, for example, habits can vary greatly depending on the destination; checking for the United States is not the same as for Europe.
Without knowing the travel frequency or past experiences of respondents, these figures remain weak indicators of general behavior.