Abstract:The purpose of lifelogging is to help users collect data for self-monitoring and reflection. We have in this study explored how lifelogging technology (a camera and a heart rate monitor) can change user experience (UX) research, and we describe a novel approach. Data was collected for three days with four participants, and a 4-6-hours co-creation workshop with stimulated recall interview was held with each of them to create an experience timeline. The timeline includes selfreported key experiences, lifelog stimulated experiences, heart rate, decisions, and valence. The results show that the number of experiences in the timeline that come from data points stimulated by the lifelogging, are as many as the self-reported data points. Lessons learned include that the use of lifelogging produces highly detailed UX research, but it is very time consuming, due to the sheer amount of data.