Designing Effective Instructional Signs with Schema Theory: Case Studies of Polystyrene Recycling

Two studies supported the hypothesis that signs designed to create a new polystyrene schema would be more effective than signs that did not address patrons' existing schemata. Schema-sensitive signs would (a) clearly define different types of polystyrene, (b) teach how clean polystyrene needed to be, and (c) keep contaminants out of the recycling bin. Study 1 showed a substantial increase in volume (from.25 to 3.5 bins recycled per day) and cleanliness (from major contamination to none), as well as corresponding increases in university cafeteria patrons' knowledge about polystyrene recycling. Study 2 replicated the behavioral effects. Relative to the baseline, with schema-sensitive signs in place, weight increased by 87% and cleanliness scores improved by 43%. Two additional interventions--prompts and persuasive signs on the garbage cans designed to interrupt the throw-it-away script--resulted in improved recycling quantity and quality, however, the increases were not significantly higher than levels achieved with only the schema-sensitive signs. The use of schema-sensitive interventions that are embedded in the total behavioral system is suggested.