Codesign and participatory design — approaches that have been used in Scandinavia since the 1970s – emphasize a shifting relationship between designers and participants, from hierarchical to collaborative. This class is an overview of how, why and when to use codesign and participatory design in design research. Specifically, codesign and participatory design offer ways of bringing together diverse groups of stakeholders around complex socio-technical issues such as health, education, transportation, technology and sustainability. Understanding and designing in these areas require deep knowledge from a variety of perspectives and sectors including non-profit, government, academia, business, technology and citizens at large. We will review examples of codesign and participatory design from a variety of design research traditions including critical making, critical design, design fiction and speculative design approaches.