This research was proposed initially to infer about Brazilian mappers. So, it was divulgated to a large audience (in the WeeklyOSM, e.g.).
If it was presented in (or also in) Brazilian Portuguese, could help to obtain more respondents.
To calculate the significance you would to study Statistics… the previous comment shows that it was not considered by the researchers/students that have lead this survey…
To do a fast calculation (there are applications that do this calculus in the Web for you), with a confidence interval of 95%…
if you have 500 to the Universe (= people in OSM Brazil Telegram group), you have to interview 218 users.
If we consider the daily active members for Brazil (almost 150 in the last week, data from OSMSTATS, Pascal Neis, checked today), you have to interview 108 users.
If you consider 80, that was the lowest level of daily active members for this week, you have to interview 67 user.
The results shows 46 respondents to Brazil…it is still very low, facing our reality.
And there are more people than what is in the Telegram, for example…
Another error is to extrapolate results obtained practically by a local reasearch (see the very low participation of the most of the countries) to the Universe (global OSM, in this case).
The idea of the research is very interesting, but it needs more scientific treatment. What you see is a poor result for most of the considered countries.
If you want, it can indicates the outreach of WeeklyOSM+Commumity OSM+some local Brazilian groups (the means of communication of this survey). But not an overview of the OSM users mean profile. Keep walking.