HOW TO - If you want to make a similar project, we have the following advice:

1. Create a good team
responsible and capable students who are interested in the project and know each other
students who know the school
the number of students is chosen according to the number of classes you plan to address
 
2. Get contacts for respondents
from school management / from former class teachers or through personal contacts
through social networks (Facebook), or via email
for the relevant result, have at least 4 classes per year (the more classes, the more accurate the result)

3. Make questionnaires
a suitable tool is Google (but other applications can be used)
it is good to divide the respondents into categories (according to the year of graduation of the secondary school), preferably on the the ones who have just entered a university, studying at a university, freshly completed and graduates who completed the education several years ago
create useful questions for each category

4. Process results into presentations
select the crucial answers, process the results in the form of graphs
verbally comment on other questions (work on individual speeches)
the presentation should be concise, clear and consistent
process the results for each category

5. Present the results toschool management and responsible persons

Useful tips to conclude:
Remember teambuilding activities (they increase performance and improve communication) and use various forms of work (eg. brainstorming, discussion, work in small groups / together)