The questionnaire was distributed at undergraduate lectures in psychology at the University of Bergen, Norway, to engineering students at Bergen College, and students at the Royal Norwegian Naval Academy during the spring of 2011. Questionnaire completion took approximately 20 minutes.
No monetary or other material incentives were offered in return for participation.
Response rate was 95%. Questionnaires were coded with unique numbers that students were asked to note and keep for later re-administration of some of the questions. They were not informed which questions