All data collection took place at school during the school day. On the day of the survey, students were asked to come to a designated room. Upon arrival, students were given an anonymous login code to access the survey. The survey included a
608-item multimedia questionnaire administered on an Internet tablet. Identification of the student's census meshblock number (based on the residential address) was used to determine the geographical location of the small area in which a student lived (approximately 90 households/ meshblock). The multimedia nature of the questionnaire meant that all students could read each question and response options themselves while listening to the questions and responses being read aloud through headphones. The average time to complete the survey was 67 minutes