school (ages 17–19); (3) use a sample of convenience since the randomisation of
students was not feasible considering the population that was readily accessible;
(4) use just one class of student in each school, with the exception of Switzerland
which included two small classes; (5) administer the questionnaires in English;
and (6) rely upon colleagues at the research sites for contact with teachers for
collaboration. The classroom teachers at each site arranged the time period for
the students to respond to the survey.
Research protocol was followed according to national requirements. In the
United States, parental consent forms were obtained from parents informing them
of the study and asking for their permission to allow their student to complete the
survey. Parental consent forms were not necessary in Chile, England and Switzerland
because the researcher did not ask for sensitive information and the data were
anonymous. Nonetheless, all data from each research site were treated as confidential
and available only to the researcher. Students were also given the option to
exclude themselves from the study. They were told that their participation or
non-participation would not affect their class grade in that course.