A university is seeking to improve recycling accuracy and reduce bin contamination in its student residential halls. The following two behavioral modification proposals have been suggested:

• Proposal A (Social Norms & Cognitive Feedback): Sending weekly automated recycling "report cards" to flat clusters that compare their flat's contamination rates with the average of the top 10% most accurate flats in their building, using green smiley or red frowny face icons.
• Proposal B (Self-Awareness & Choice Architecture): Redesigning communal bin rooms to use transparent sorting bins with shape-coded lid apertures (e.g., round slots for tins, flat slots for paper) and mounting large mirrors directly above the bins.