Creativity and critical thinking are key skills for complex, globalised and increasingly digitalised economies and societies. While teachers and education policy makers consider creativity and critical thinking as important learning goals, it is still unclear to many what it means to develop these skills in a school setting. To make it more visible and tangible to practitioners, the OECD worked with networks of schools and teachers in 11 countries to develop and trial a set of pedagogical resources that exemplify what it means to teach, learn and make progress in creativity and critical thinking in primary and secondary education. Through a portfolio of rubrics and examples of lesson plans, teachers in the field gave feedback, implemented the proposed teaching strategies and documented their work. Instruments to monitor the effectiveness of the intervention in a validation study were also developed and tested, supplementing the insights on the effects of the intervention in the field provided by the team co-ordinators. What are the key elements of creativity and critical thinking? What pedagogical strategies and approaches can teachers adopt to foster them? How can school leaders support teachers’ professional learning? To what extent did teachers participating in the project change their teaching methods? How can we know whether it works and for whom? These are some of the questions addressed in this book, which reports on the outputs and lessons of this international project.