Methodology
Sampling
Students participating in the study were randomly selected from a list of high school’s students enrolled in Grade 9 during the 2011–2012 school year, generated by the Ministère de l’Éducation du Québec. This sampling strategy resulted in a representative sample of French-speaking Grade 9 students in Quebec, stratified by sex, socioeconomic background, region, and public or private school sector.
Data collection procedure
Participants received a questionnaire annually, either by mail or online, for six years. Each participant was required to sign an informed consent form, and parents provided consent for their minor children to participate. Participants could individually withdraw from the study at any time or choose not to complete a particular wave of data collection. Families received compensation at each wave for their participation.
Learn more about the study context.