The experiment was part of a geography class taught to 4 different class groups of 6th year general-oriented
technical education (n=77): 2 groups studying Social and Technical Sciences and 2 groups studying Nursing
Youngsters and Disabled. Per study field one group was randomly assigned to a condition. The school is based in
Ghent, the Dutch speaking part of Belgium. Geography is allocated 2 periods in the timetable (total 32 periods) of
both groups, which results in geography being a subject of minor importance. Our experiment was scheduled mid-
February 2012. Consequently, students should share a nearly identical background knowledge concerning the topic
and course.