Australian secondary school students' use of tobacco, alcohol, and over-the-counter and illicit substances in 2011
Principals of selected schools were contacted and permission to conduct the survey at the school was sought. If a school refused, they were replaced by the school geographically nearest to them within the same education sector.
The study aimed to have 80 students from each participating school complete the survey. The original procedure for student selection was to randomly select students from the school roll for the relevant year levels. To this end, a member of the research team randomly selected 20 students (and six replacements) from each of the four year levels in each junior school participating; while for senior schools, 40 students (and 12 replacements) were sampled from each of Years 11 and 12. In 2011 this procedure was used in schools that did not require active parental consent.
Since the 2000s, an increasing number of education authorities and individual schools have required that active parental consent be obtained before students participate in the study. Active parental consent requires that the student return a consent form showing that their parents have approved their participation in the study. If a consent form is not returned, the student cannot participate in the study. This requirement can reduce the participation rate of students, unless teachers actively assist in reminding them to return their consent forms. Past experience has indicated that teachers are more likely to assist in this task, and consequently response rates improved, when students are surveyed in an intact class rather than from a random selection of students across a year level. In states and territories that required active parental consent, rather than selecting a random sample of students, intact classes of students were randomly selected within the required year levels. Only classes where students were not selected on any ability or performance measure were included in this process. This ensured a representative cross-section of the student population in each year level. Surveying students from intact classes was also followed when principals of individual schools were otherwise unable to permit participation of their school.
Following the protocol used in past surveys, members of the research team administered the pencil-and-paper questionnaire to groups of up to 20 students on the school premises (or a class if intact classes were surveyed). If a student from the sample list was not present at the time of the survey, a student from the equivalent year level on the replacement list was surveyed (where intact classes were used, there were no replacements). Students from different year levels were surveyed together, and students answered the questionnaire anonymously.
The policy of the education departments in each state and territory, and the policies of individual schools determined whether teachers remained in the room when the survey was being administered. Most schools required this in 2011, with 90% of students completing the questionnaire in the presence of teachers. If a teacher was present when the survey was being conducted, they were asked to remain at the front or back of the room and not to participate in the survey session. In general, there were few differences in the responses of students completing the survey with or without a teacher present. The main differences found were lifetime and past year use of cannabis and ecstasy among 16- and 17-year-olds, and lifetime, past year and past month use of cannabis among 12 to 15-year-olds. For younger students, prevalence estimates were higher when the teacher was absent, but for older students, prevalence estimates were lower when the teacher was absent.