Students are more motivated because they actively participate and share their experiences. Many schools are made up of students of many ethnic origins. If this is not the case, perhaps exchange students can be interviewed. If there are no students of other ethnic origins, then people of other ethnic origins in the community can be interviewed. They can exchange their list of questions with another group who will make suggestions for editing.
Verification is necessary only if the lack of grammatical accuracy interferes with communication.
Cite specific examples. Conduct the survey. It would be best if the students could conduct the survey in French, but this may not be realistic. The target groups are people of other ethnic origins and they may not speak French. The group will compile their results and report their findings to the class.