Through hands-on classroom studies, a group of researchers from the University of Gothenburg, Sweden, show how events and opportunities are affected by classroom conditions and thus have different didactical consequences for teaching and learning in different subjects. In a concluding essay, the book itself and its contributions are placed in an international and historical context by Professor Kirsti Klette, Oslo University, Norway. The authors share an ambition to show in practical terms the strengths of classroom studies’ contribution to didactic research.