The questionnaire asks the subject to rate his or her probability of falling asleep on a scale of increasing probability from 0 to 3 for eight different situations that most people engage in during their daily lives, though not necessarily every day. The scores for the eight questions are added together to obtain a single number.
The survey inquires about the subject's likelihood of dozing off on a scale of rising probability from 0 to 3 for eight common daily activities that people typically participate in, although not necessarily every day. The scores from all eight questions are summed up to yield a single figure.