Based on information obtained from a literature review, norms and prompts were incorporated into a pilot program designed to improve participation in curbside recycling. City blocks in Denver were randomly divided into groups which received different behavioral interventions. One group had volunteer block leaders inform their neighbors about the program and also provided monthly prompts to recycle. Another group received pamphlets each month as a reminder just prior to recycling day. Still another group received only the informational brochure. Finally, one group served as a control condition. Data collection occurred by counting the number of times a resident recycled during a 7 week period.
Although all interventions improved particiaptions, it is clearly the block leaders who had the most significant impact on behavior. Fully one third of residents were recycling by the end of the 7 week period as compared to the control condition. Also, prompts increased participation by 20%.