This open access book addresses the growing trend in the field of early childhood education and care (ECEC) research named collaborative knowledge building in which researchers and ECEC personnel collaborate. This kind of research encompasses a number of approaches, such as design studies, action studies, Learning Studies, Lesson Studies, and combined research and development studies.There are important differences between these approaches, but they also share some features, which makes it possible to see them as examples of a particular tradition of knowledge building. Collaborative...