Book excerpt: This book provides an overview and discussion of the evidence base of effective school inspections; reflecting on issues of validity and reliability of school inspections in relation to school effectiveness research, unintended consequences and emergent roles and responsibilities of Inspectorates of Education. Chapters include findings from systematic literature reviews and primary research while also presenting a range of practical examples from inspections systems from all over the world. The book provides relevant background materials for Inspectorates of Education who aim to improve the effectiveness of their systems and working methods, as well as clear examples for researchers aiming to analyse and understand the effectiveness of these systems. The final chapter reflects on changes in the current education landscape and discusses newer models of school inspections that fit within a more decentralized inspection system.