NowAndThen

People frequently post their photos on social network sites (e.g. Facebook, Instagram) as a way to share memorable moments, emotions, or locations visited. While sharing photos with the same subjects as past photos could lead to user reminiscence and potentially create valuable benefits, existing products still cannot support this adequately. Based on a survey on user habits in sharing and revisiting photos on social network sites, we propose NowAndThen, a photo recommendation concept and tool that assists reminiscence when sharing photos on social network sites. By combining visual features of the photos and associated tags, a prototype we developed can recommend old photos that have common subjects with the user's current photos of interest. Our study with the prototype shows that this approach can help users positively revive past memories and connections with their friends. In addition, our results include various design insights and implications for future reminiscence-support systems.