Mood meter: counting smiles in the wild

In this study, we created and evaluated a computer vision based system that automatically encouraged, recognized and counted smiles on a college campus. During a ten-week installation, passersby were able to interact with the system at four public locations. The aggregated data was displayed in real time in various intuitive and interactive formats on a public website. We found privacy to be one of the main design constraints, and transparency to be the best strategy to gain participants' acceptance. In a survey (with 300 responses), participants reported that the system made them smile more than they expected, and it made them and others around them feel momentarily better. Quantitative analysis of the interactions revealed periodic patterns (e.g., more smiles during the weekends) and strong correlation with campus events (e.g., fewer smiles during exams, most smiles the day after graduation), reflecting the emotional responses of a large community.