Book excerpt: Western societies are calling for speedy change in agriculture and the agrifood industries to incorporate new quality criteria into the goods they produce. To promote these changes what scientists must develop are not universally implementable technical solutions, but self-diagnosis methods to be used by agricultural producers and their advisors. They also need to evolve new procedures for research intervention in collective organisations. There is a need for new individual and collective learning and organisation processes based on transdisciplinarity and co-learning among researchers, development professionals, decision makers and farmers. In this book, scientists from ten industrialised countries describe and reflect on their theoretical and practical experience of the different forms of learning they experimented with.