A literature review revealed that prompts were an effective tool in controlling litter. Therefore, verbal and visual prompts were incorporated into a pilot program designed to curb littering at Australian high schools. The number of littered items in and around the cafeteria was counted after lunch every day of the program. First, verbal reminders were given during morning assemblies. Second, sign prompts that read "Please place your litter in the bin provided" were posted. Third, the verbal reminders were removed so that only the visual prompt remained. Finally, measurement was taken six weeks following the removal of all prompts.
Verbal and visual prompts were most effective when used in combination. On average, the number of littered items was reduced to 2.5 in the cafeteria compared to 7.3 items before the intervention was introduced.