This research proposes “SmileWave”, a system for revealing smile-based emotional contagion, propagation effect of the similar emotion through smiley facial expression, on the social network where users interact with each other through web-based user interface rather than in-person interaction. SmileWave is a photo-based social networking service. It detects the changes of user’s smile degree when the user looks at posted smile photos of others. For extensive evaluation of SmileWave, we conducted multiple in-the-wild studies with 50 participants for 3 weeks (phase 1) and with 10 participants for 3 weeks (phase 2). In the phase 1 experiment, we confirmed the smile-based emotional contagion effect on Smile- Wave. The users’ smile degree improved by 27% when the user looked at posted smile selfies. The result also proved that there is a stronger effect on smile-based emotional con- tagion when the examinee and the person in the photo are in close relationship. Moreover, in the second phase, we found that there is a higher effect on smile-based emotional contagion in case of viewing selfies with higher smile degree, both in the short term duration and the longer duration.
In recent years, progressed aging population in Japan, reduction of communication within the community and the lonely death of aged residence have become major problems. In addition, many researches and services have been proposed in accordance with the developemt of information technology. However, monitoring the elderly people such as pasting the sensors on thier body and using the camera can violate their privacy. Therefore, we proposed the eldery paticipation watching system instead of unilaterally watching system and evaluated the potential of this system in a real community.