Two studies were conducted to measure the relative frequency of use of stairs and escalators and to assess the impact of an intervention designed to increase physical activity. The first study assessed the effects of intermittent use of the intervention. A total of 21,091 observations were made of people going up stairs or escalators in three public places (shopping mall, train station, bus terminal). Persons carrying baggage or items larger than an attache case were excluded, as were children. Observations at each site were made once a week for 8 weeks, on the same day of the week during the same hours: 11:30 a.m. to 1:00 p.m. for the shopping mall, 7:30 a.m. to 9:30 a.m. for the train station, and 3:30 p.m. to 5:30 p.m. for the bus terminal. The first 2 weeks were considered the baseline period with no intervention. The next 2 weeks consisted of observations made with the sign displayed. The final 4 weeks were a repeat of the first 4 weeks (ABAB experimental design).
The second study was designed to address two issues raised by the first study. First, repeated exposure to the intervention was evaluated. Second, the long-term maintenance of changes in activity was measured by presumably observing the same group of people over time. Observations were made at a commuter train station in the business district from 7:30 a.m. to 9:00 a.m. on weekdays. A total of 24,603 observations were made. The authors postulate that they were likely observing the same people each day since observations were made before commercial businesses opened, there were few tourists in this part of the city, and because the same trains entered the station during the observation hours. Baseline observations were made for 5 consecutive days. The same sign as the one used in study 1 was then displayed for 15 consecutive days. A 10-day withdrawal-of-intervention phase followed (no sign). Then two 1-week follow-up phases were completed (no sign), 1 month and 3 months after the last day of the intervention (ABA experimental design).