The study presented in this book is embedded within the -Video Study of Physics Lessons- conducted by the Institute for Science Education at the University of Kiel. The study aims at analysing whether physics lessons taught by a sample of German physics teachers meet key characteristics of constructivist learning environments and constructivist teaching sequences as identified in the literature. Classroom learning environments are assessed using a category system called the Constructivist Oriented Science Classrooms (COSC), while teaching sequences are assessed using a category system called the Constructivist Teaching Sequences (CTS). This book presents the results of the analyses as well as the correlations between the appearances of the characteristics of constructivist-oriented lessons and students' achievement and students' interest."