It is self-reported and relative to others. > "The questionnaire asks how often students are willing to travel for work, the number of hours per week they are

It is self-reported and relative to others. > "The questionnaire asks how often students are willing to travel for work, the number of hours per week they are willing to work, and their desired compensation. They were also asked to rate their ambition relative to their most recent work colleagues and their tendency to lead in day-to-day interactions on a 1-to-5 scale."