Welcome to this free-of-charge online seminar, organized by Mistra REES, about bottom-up vs. top-down research. Based on finalized and ongoing research activities, the aim is to present, discuss, and disseminate the pros and cons of these research approaches regarding research related to transitions towards a circular economy. One of the presented research activities is the Mistra REES program, which aims at creating knowledge, co-produced by industry and academia, on how a transition towards a circular and sustainable economy can be facilitated.