Participants
30 middle school/ high school classes (about 750 students and 30 teachers)
2 conditions with equivalent characteristics (subjects concerned, class level, gender and seniority of the teacher):
- Experimental condition (15 teachers and their students)
- Control condition (15 teachers and their students)
2 conditions with equivalent characteristics (subjects concerned, class level, gender and seniority of the teacher):
- Experimental condition (15 teachers and their students)
- Control condition (15 teachers and their students)