This book features 35 of best papers from the 9th European Science Education Research Association Conference, ESERA 2011, held in Lyon, France, September 5th-9th 2011. The ESERA international conference featured some 1,200 participants from Africa, Asia, Australia, Europe as well as North and South America offering insight into the field at the end of the first decade of the 21st century.This book presents studies that represent the current orientations of research in science education and includes studies in different educational traditions from around the world. It is organized into six parts around the three poles (content, students, teachers) and their interrelations of science education: after a general presentation of the volume (first part), the second part concerns SSI (Socio-Scientific Issues) dealing with new types of content, the third the teachers, the fourth the students, the fifth the relationships between teaching and learning, and the sixth the teaching resources and the curricula.