Once treatment ended, the subjects ceased
self-monitoring and the follow-up began. During
follow-up, the subjects were contacted by
telephone or in person every 2 weeks and told
to record the number and types of all caffeinecontaining
beverages they drank for the next
2 days. They were contacted the day after the
follow-up and their reports were recorded. In
addition, they mailed their records to the experimenters
or presented them in person.